Ferrous magnetic materials

Abstract

Soft magnetic materials may include a''-Fe16(PxZ1-x)2 or a mixture of α''-Fe16P2 and α"-Fe16Z2, where Z includes at least one of C, B, Al, Si, S, or O, and x is a number greater than zero and less than one. Techniques for forming soft magnetic materials are also described.

Description

Docket No.: 1008-365WO01 / 2023-285 FERROUS MAGNETIC MATERIALS CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 584,587, filed on September 22, 2023, which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present disclosure relates to ferrous magnetic materials and techniques for forming ferrous magnetic materials, for example, soft magnetic materials. BACKGROUND

[0003] Soft magnetic materials possess relatively low coercivity, while hard magnetic materials possess relatively high coercivity. For example, soft magnetic materials may be used in transformer and inductor cores, magnetic recording write heads, microwave devices, magnetic shielding, and the like. The base element iron (Fe) is inexpensive and widely available, in contrast to rare earth elements in rare earth element-based magnets, which are costly and subject to supply availability risks. SUMMARY

[0004] The present disclosure describes soft magnetic materials including iron- phosphorous (Fe-P) phase domains, and techniques for forming soft magnetic materials that include Fe-P phase domains. The magnetic materials may include magnetically soft materials, or may include magnetically soft phase domains. Fe-P based magnetic materials may provide an alternative to magnets that include a rare earth element, for example, while having a relatively high saturation magnetization and magnetic anisotropy constant. Additionally, Fe and P are abundant elements, and thus are relatively inexpensive and easy to procure.

[0005] In some examples according to the present disclosure, an example soft magnetic material includes ĮƎ-Fe16(PxZ1-x)2 RU^D^PL[WXUH^RI^ĮƎ-Fe16P2 DQG^ĮƎ-Fe16Z2. Z includes at least one of C, B, Al, Si, S, or O, and x is a number greater than zero and less than one.

[0006] In some examples according to the present disclosure, an example soft magnetic material includes a phospho-carbon-ferrous domain comprising a plurality of Fe6P clusters and a plurality of Fe6C clusters.Docket No.: 1008-365WO01 / 2023-285

[0007] Techniques for forming the soft magnetic materials are also described.

[0008] The details of one or more examples of the techniques of this disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the techniques will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The summary, as well as the following detailed description, is further understood when read in conjunction with the appended drawings. For the purpose of illustrating the disclosure, examples are shown in the drawings; however, the disclosure is not limited to the specific techniques, compositions, and devices disclosed. In addition, the drawings are not necessarily drawn to scale.

[0010] FIG. 1A is a conceptual diagram illustrating a front view of a unit cell of Fe16P2lattice.

[0011] FIG. 1B is a conceptual diagram illustrating a perspective view of the unit cell of FIG. 1A.

[0012] FIG. 2A is a conceptual diagram illustrating a front view of a Fe-P cluster-atom cell.

[0013] FIG. 2B is a conceptual diagram illustrating a perspective view of the Fe-P cluster-atom cell of FIG. 2A.

[0014] FIG. 3 is a conceptual diagram illustrating a perspective view of an extended lattice including a plurality of Fe-P cluster-atom cells.

[0015] FIG. 4 illustrates a flowchart of a technique for making a ferrous hard magnet including Fe16P2.

[0016] FIG. 5 is a conceptual diagram illustrating a perspective view of DQ^ĮƎ-Fe16X2unit cell, where X = P, C, B, Al, Si, S, or O.

[0017] FIG. 6 is a conceptual diagram illustrating a soft magnetic material including GRPDLQV^RI^ĮƎ-Fe16P2 DQG^GRPDLQV^RI^ĮƎ-Fe16Z2, where Z = C, B, Al, Si, S, or O.

[0018] FIG. 7 is a conceptual and schematic diagram illustrating an example CVD system IRU^IRUPLQJ^D^PDJQHWLF^PDWHULDO^LQFOXGLQJ^ĮƎ-Fe16(PxZ1-x)2 RU^D^PL[WXUH^RI^ĮƎ-Fe16P2 DQG^ĮƎ-Fe16Z2, where Z includes at least one of C, B, Al, Si, S, or O.

[0019] FIG. 8 is a conceptual and schematic diagram illustrating an example CVD V\VWHP^IRU^IRUPLQJ^D^PDJQHWLF^PDWHULDO^LQFOXGLQJ^ĮƎ-Fe16(PxZ1-x)2 RU^D^PL[WXUH^RI^ĮƎ-Fe16Z2 DQG^ĮƎ-Fe16P2, where Z includes at least one of C, B, Al, Si, S, or O.Docket No.: 1008-365WO01 / 2023-285

[0020] FIG. 9 is a conceptual and schematic diagram illustrating an example system for forming a coating including Fe, P, and C over a substrate using liquid phase epitaxy.

[0021] FIG. 10 is a conceptual and schematic diagram illustrating an example article including a substrate and a multilayer magnetic material including a first set of layers LQFOXGLQJ^ĮƎ-Fe16P2 DQG^D^VHFRQG^VHW^RI^OD\HUV^LQFOXGLQJ^ĮƎ-Fe16Z2, where Z includes at least one of C, B, Al, Si, S, or O.

[0022] FIG. 11 is a flow diagram that illustrates an example technique for forming a bulk PDJQHWLF^PDWHULDO^LQFOXGLQJ^ĮƎ-Fe16(PxZ1-x)2 RU^D^PL[WXUH^RI^ĮƎ-Fe16P2 DQG^ĮƎ-Fe16Z2, where Z includes at least one of C, B, Al, Si, S, or O.

[0023] FIG. 12 illustrates a conceptual diagram of an apparatus with which the iron wire or sheet can be strained and exposed to P and C.

[0024] FIG. 13 is a flow diagram that illustrates an example technique for forming a PDJQHWLF^PDWHULDO^LQFOXGLQJ^ĮƎ-Fe16(PxZ1-x)2or a PL[WXUH^RI^ĮƎ-Fe16P2DQG^ĮƎ-Fe16Z2, where Z includes at least one of C, B, Al, Si, S, or O.

[0025] FIG. 14 is a conceptual diagram illustrating a milling apparatus that may be used to mill an iron-containing raw material with a P source and / or a C source.

[0026] FIG. 15 is a flow diagram of an example technique for forming a workpiece LQFOXGLQJ^ĮƎ-Fe16(PxC1-x)2 RU^D^PL[WXUH^RI^ĮƎ-Fe16P2 DQG^ĮƎ-Fe16C2.

[0027] FIG. 16 illustrates a starting Zener-ordering model of Fe16P2unit cell for molecular dynamics (MD) relaxation. The starting unit cell includes a combination of two sublattice cells, a body-center-cubic (BCC) Fe unit cell and a second BCC P unit cell.

[0028] FIG. 17A illustrates a front view of a final unit cell including an Į^-Fe16P2lattice resulting from a run of MD simulation performed on the starting unit cell of FIG. 16.

[0029] FIG. 17B illustrates an elevated view of the final unit cell of FIG. 17A.

[0030] FIG. 17C illustrates a perspective view of the final unit cell of FIG. 17A.

[0031] FIG. 18A illustrates a front view showing selected inter-atomic distances in the final unit cell of FIG. 17A.

[0032] FIG. 18B illustrates a perspective view showing selected inter-atomic distances in the final unit cell of FIG. 18A.

[0033] FIG. 19A illustrates a front view of a final unit cell including an Į^-Fe16N2 lattice resulting from a run of MD simulation performed on a starting unit cell similar to FIG. 16 in which P is replaced with N.

[0034] FIG. 19B illustrates an elevated view of the final unit cell of FIG. 19A.Docket No.: 1008-365WO01 / 2023-285

[0035] FIG. 20A is a chart illustrating a calculated relationship between bond energy (interatomic potentials) and interatomic distance between pairs of Fe-P, Fe-N, and Fe-Fe atoms calculated using Modified Embedded-Atom Method (MEAM) potentials.

[0036] FIG. 20B is a chart illustrating a calculated relationship between atomic force and interatomic distance between pairs of Fe-P, Fe-N, and Fe-Fe atoms calculated using MEAM potentials.

[0037] FIG. 21 is a chart illustrating an energy minimization process leading to the ground state of BCT crystal lattice in an MD simulation.

[0038] FIG. 22 illustrates changes in simulated lattice structures in an energy minimization process from a starting BCC-supercell structure to a BCT- Į^^VWUXFWXUH^DW^ intervals over a MD time of 15000 femtoseconds.

[0039] FIG. 23 is a chart illustrating energy minimization process in the process of FIG. 22.

[0040] FIG. 24 illustrates a relaxed structure of BCT Fe16P2 obtained by a density- functional theory (DFT) simulation run.

[0041] FIG. 25A illustrates a Fe16P2triclinic variant structure obtained by DFT simulation.

[0042] FIG. 25B illustrates a Fe16P2 iron-nitride-like variant structure obtained by DFT simulation.

[0043] FIG. 25C illustrates a Fe16P2body centered orthorhombic variant structure obtained by DFT simulation.

[0044] FIG. 25D illustrates a Fe16P2variant structure obtained by DFT simulation that is similar to another structure obtained by MD simulation. DETAILED DESCRIPTION

[0045] The present disclosure may be understood more readily by reference to the following detailed description taken in connection with the accompanying figures and examples, which form a part of this disclosure. It is to be understood that this disclosure is not limited to the specific devices, methods, applications, conditions or parameters described and / or shown herein, and that the terminology used herein is for the purpose of describing particular examples and is not intended to be limiting of the claims. When a range of values is expressed, another example includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another example. AllDocket No.: 1008-365WO01 / 2023-285 ranges are inclusive and combinable. Further, a reference to values stated in a range includes each and every value within that range.

[0046] It is to be appreciated that certain features of the disclosure which are, for clarity, described herein in the context of separate examples, may also be provided in combination in a single example. Conversely, various features of the disclosure that are, for brevity, described in the context of a single example, may also be provided separately or in any subcombination.

[0047] The present disclosure generally relates to ferrous magnetic materials and techniques for forming ferrous magnetic materials. The materials may include hard magnetic materials or soft magnetic materials. The materials include Fe-P phase domains, for example, at least one of a Fe16P2 phase domain, a Fe8P phase domain, a Fe16(PxZ1-x)2 phase domain, or a Fe8(PxZ1-x) phase domain, where x is greater than zero and less than one, and where Z includes at least one of C, B, Al, Si, S, or O. In some examples, magnetic materials may include combinations of various Fe-P phases, for example, combinations of phases of magnetically hard or magnetically soft material.

[0048] Magnetic materials that include a Fe16P2phase may provide a relatively high energy product, for example, at least about 20 MGOe, or at least about 30 MGOe. The energy product of a permanent magnetic is proportional to the product of remanent coercivity and remanent magnetization. A relatively higher energy product can lead to increased efficiency of the permanent magnet when used in motors, generators, or the like.

[0049] Additionally, magnetic materials that include a Fe16P2 phase may not need to include rare earth elements to provide a high energy product, which may reduce a materials cost of the magnetic materials and may reduce an environmental impact of producing the magnetic materials. Thus, the present disclosure describes magnetic materials, for example, hard magnetic materials, including a Fe16P2phase.

[0050] The present disclosure also describes soft magnetic materials include Fe-P phase domains. For example, a soft magnetic material may include ĮƎ-Fe16(PxZ1-x)2 RU^Įƍ-Fe8(PxZ1- x), or a mixture of at least one RI^ĮƎ-Fe16P2 RU^Įƍ-Fe8P DQG^DW^OHDVW^RQH^RI^ĮƎ-Fe16Z2 RU^Įƍ-Fe8Z, where Z includes at least one of C, B, Al, So, S, or O, and x is a number greater than zero and less than one. ,Q^VRPH^H[DPSOHV^^WKH^PDJQHWLF^PDWHULDO^LQFOXGLQJ^ĮƎ-Fe16(PxZ1-x)2 RU^Įƍ- Fe8(PxZ1-x^^^RU^D^PL[WXUH^RI^DW^OHDVW^RQH^RI^ĮƎ-Fe16P2 RU^Įƍ-Fe8P DQG^DW^OHDVW^RQH^RI^ĮƎ-Fe16Z2 RU^Įƍ-Fe8Z, may include a relatively high magnetic saturation, such as greater than about 200 emu / gram, greater than about 220 emu / gram, or greater than about 250 emu / gram. In DGGLWLRQ^^LQ^VRPH^H[DPSOHV^^WKH^PDJQHWLF^PDWHULDO^LQFOXGLQJ^ĮƎ-Fe16(PxZ1-x)2 RU^Įƍ-Fe8(PxZ1-Docket No.: 1008-365WO01 / 2023-285 x^^^RU^D^PL[WXUH^RI^DW^OHDVW^RQH^RI^ĮƎ-Fe16P2 RU^Įƍ-Fe8P DQG^DW^OHDVW^RQH^RI^ĮƎ-Fe16Z2 RU^Įƍ-Fe8Z may include a relatively low coercivity.

[0051] The coercivity of the soft magnetic material may be relatively low, for example, less than about 10 Oersteds (Oe), while having a relatively high magnetic saturation, for example, at least 200 emu / gram. The combination of relatively high magnetic saturation and relatively low coercivity may make the soft magnetic material a candidate material for use in transformer and inductor cores, magnetic recording media write heads, microwave devices, magnetic shielding, and the like. In some examples, the magnetic PDWHULDO^LQFOXGLQJ^ĮƎ-Fe16(PxZ1-x)2 RU^Įƍ-Fe8(PxZ1-x^^^RU^D^PL[WXUH^RI^DW^OHDVW^RQH^RI^ĮƎ-Fe16P2 RU^Įƍ-Fe8P and at least RQH^RI^ĮƎ-Fe16Z2RU^Įƍ-Fe8Z also may possess high magnetic permeability, high frequency response, and the like.

[0052] For purposes of description only, certain descriptions of soft magnetic materials may SULPDULO\^UHIHU^WR^ĮƎ-Fe16(PxZ1-x)2RU^D^PL[WXUH^RI^ĮƎ-Fe16P2DQG^ĮƎ-Fe16Z2. However, VLPLODU^SULQFLSOHV^DQG^H[DPSOHV^PD\^DSSO\^WR^DQG^LQFOXGH^Įƍ-Fe8(PxZ1-x) or a PL[WXUH^RI^Įƍ- Fe8P DQG^Įƍ-Fe8Z, or mixtures between these different phases.

[0053] In some examples, a soft magnetic material may include a multilayer structure WKDW^LQFOXGHV^DOWHUQDWLQJ^OD\HUV^RI^ĮƎ-Fe16P2 DQG^ĮƎ-Fe16Z2, where Z includes at least one of C, B, Al, Si, S, or O. In other examples, the soft magnetic material may include a mixture LQFOXGLQJ^ĮƎ-Fe16P2SKDVH^GRPDLQV^DQG^ĮƎ-Fe16Z2phase domains. In other examples, the PDJQHWLF^PDWHULDO^PD\^LQFOXGH^ĮƎ-Fe16(PxZ1-x)2phase domains, wherein x is greater than zero and less than one. %\^FRQWUROOLQJ^WKH^UDWLR^RI^ĮƎ-Fe16P2 SKDVH^GRPDLQV^DQG^ĮƎ-Fe16Z2 phase domains or the ratio of P DWRPV^DQG^=^DWRPV^LQ^ĮƎ-Fe16(NxZ1-x)2, the coercivity of the magnetic material may be controlled.

[0054] )RU^H[DPSOH^^ĮƎ-Fe16P2 may have a magnetic easy axis lying along the <001> D[LV^^ZKLOH^ĮƎ-Fe16Z2may have an easy axis lying perpendicular to the <001> axis, such as in the <010> axis or the <100> axis. Because the easy axes are perpendicular, the magnetic DQLVRWURS\^RI^ĮƎ-Fe16P2 DQG^ĮƎ-Fe16Z2 may cancel each other when mixed together, reducing WKH^FRHUFLYLW\^RI^WKH^PDJQHWLF^PDWHULDO^LQFOXGLQJ^D^PL[WXUH^RI^ĮƎ-Fe16P2 DQG^ĮƎ-Fe16Z2. SLPLODUO\^^LQ^ĮƎ-Fe16(PxZ1-x)2, P atoms and Z atoms may distort the iron crystalline structure in opposite ways, such that mixing P atoms and Z atoms reduces magnetocrystalline DQLVRWURS\^DQG^FRHUFLYLW\^RI^WKH^PDJQHWLF^PDWHULDO^FRPSDUHG^WR^ĮƎ-Fe16P2 DORQH^RU^ĮƎ-Fe16Z2 alone. %RWK^ĮƎ-Fe16P2DQG^ĮƎ-Fe16Z2possess relatively high saturation magnetizations, such WKDW^D^PDWHULDO^LQFOXGLQJ^D^PL[WXUH^RI^ĮƎ-Fe16P2 DQG^ĮƎ-Fe16Z2 may have relatively high VDWXUDWLRQ^PDJQHWL]DWLRQ^^UHJDUGOHVV^RI^WKH^UDWLR^RI^ĮƎ-Fe16P2 WR^ĮƎ-Fe16Z2.Docket No.: 1008-365WO01 / 2023-285

[0055] Hard and soft magnetic materials according to the present disclosure may be fabricated by any of a variety of techniques. Example techniques described herein include melt-spinning, chemical vapor deposition (CVD), liquid phase epitaxy (LPE), physical vapor deposition (PVD), sputtering, ion implantation, phosphorizing and carbonizing a workpiece under an applied strain, milling an iron-containing powder in presence of P (and / or C, B, Al, Si, S, or O), a continuous casting, pressing, and quenching process, annealing, or the like. Other example techniques include molecular beam epitaxy (MBE) and low temperature epitaxy.

[0056] In some examples according to the present disclosure, a magnetic material includes DQ^Į^-Fe16P2phase domain. TKH^Į^-Fe16P2phase domain may include body centered tetragonal (BCT) unit cells or variants thereof.

[0057] FIG. 1A is a conceptual diagram illustrating a front view of a unit cell of Fe16P2. FIG. 1B is a conceptual diagram illustrating a perspective view of the unit cell of FIG. 1A. In some examples, the unit cell is a body centered tetragonal (BCT) cell. As shown in FIGS. 1A and 1B, the BCT cell includes P atoms aligned along the (002) (iron) crystal planes. The unit cell (e.g., BCT cell) is distorted such that the length of the unit cell along the <001> axis is approximately 8.00 DQJVWURPV^^Ⴒ^^ZKLOH^WKH^OHQJWK^RI^WKH^XQLW^FHOO^DORQJ^WKH^^^^^!^DQG^ <100> axes is approximately 5.60 Ⴒ^^ 7KH^ĮƎ-Fe16P2 unit cell may be referred to as a BCT unit cell when in the strained state. :KHQ^WKH^ĮƎ-Fe16P2unit cell is in the strained state, the <001> axis may be referred to as the c-axis of the unit cell. The c-axis may be the magnetic HDV\^D[LV^RI^WKH^ĮƎ-Fe16P2 unit cell. In other worGV^^ĮƎ-Fe16P2 crystals exhibit magnetic anisotropy.

[0058] ĮƎ-Fe16P2has high saturation magnetization and magnetic anisotropy constant. The high saturation magnetization and magnetic anisotropy constants result in a magnetic energy product that may be higher than rare earth magnets. Additionally, Fe and P are abundant elements, and thus are relatively inexpensive and easy to procure.

[0059] Calculations based on density functional theory (DFT) show that the PDJQHWRFU\VWDOOLQH^DQLVRWURS\^RI^ĮƎ-Fe16P2 may be in a range from about 1x107to about 2x107erg / cm3. ĮƎ-Fe16P2also has a relatively high theoretical magnetic saturation moment in a range from about 2.0 to 2.8 %RKU^PDJQHWRQV^SHU^LURQ^DWRP^^B / Fe.

[0060] In some examples, the Fe-P lattice may include a cluster-atom cell. Thus, a magnetic material may include a lattice including a phospho-ferrous domain including a plurality of Fe-P clusters.Docket No.: 1008-365WO01 / 2023-285

[0061] FIG. 2A is a conceptual diagram illustrating a front view of a Fe-P cluster-atom cell. FIG. 2B is a conceptual diagram illustrating a perspective view of the cluster-atom cell of FIG.2A. FIG. 3 is a conceptual diagram illustrating a perspective view of an extended lattice including a plurality of Fe-P cluster-atom cells.

[0062] As shown in FIGS. 2A and 2B, each cluster-atom cell may include an Fe6P cluster. For example, the cluster may include P at a geometric center of an octahedral arrangement of Fe. In some examples, each cluster of the plurality of Fe6P clusters includes P at a geometric center of an octahedral arrangement of Fe. There may be a correspondence between BCT unit cells and the Fe6P clusters. For example, atoms of the Fe6P clusters may occupy sites corresponding to sites in the BCT unit cells. Thus, an extended lattice may be characterized as including a plurality of Fe6P clusters, or as including a plurality of BCT unit cells. For example, the interatomic distance between a P atom and surrounding Fe atoms may be substantially the same in both Fe6P clusters and BCT unit cells.

[0063] Regardless of whether the Fe-P domains are characterized as including Fe6P clusters or BCT unit cells, the magnetic material may be free of neodymium (Nd). In some examples, the magnetic material is free of any rare-earth element.

[0064] The magnetic material may further include a dopant. For example, the dopant may be present within Fe-P phase domains, or in inter-domain regions. The dopant may include at least one of Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, Pt, Au, Sm, C, Pb, W, Ga, Y, Mg, Hf, Ge, Al, or Ta.

[0065] The magnetic material may further include a phase stabilizer. For example, the phase stabilizer may be present within Fe-P phase domains, or in extra-domain regions. The phase stabilizer includes at least one of B, Al, C, Si, O, Co, Cr, Mn, Ti, V, or S.

[0066] The magnetic material may have a relatively high energy product. For example, the magnetic material may have an energy product of at least 20 MGOe. In some examples, the magnetic material has an energy product of at least 40 MGOe, or at least 60 MGOe.

[0067] The magnetic material may have a relatively high magnetic coercivity. For example, the magnetic material may have a coercivity of at least 4 kOe, or at least 5 kOe, or at least 6 kOe, or at least 7 kOe. In some examples, the magnetic material has a coercivity of at least 8 kOe.

[0068] The magnetic material may assume any suitable form, including a particulate or a powdered form, or an aggregated or bulk form.

[0069] In some examples, a bulk permanent magnetic material includes the magnetic material including Fe-P phase domains. In some examples, D^SOXUDOLW\^RI^Į^-Fe16P2 phaseDocket No.: 1008-365WO01 / 2023-285 domains are distributed throughout a volume of the bulk permanent magnetic material. In some examples, the bulk permanent magnetic material may include at least one additional domain, for example, a non-magnetic domain, or a soft magnetic domain. The Fe16P2phase may be magnetically coupled to a magnetically soft domain by exchange spring coupling, which may effectively harden the magnetically soft material and provide magnetic properties for the bulk material similar to those of a bulk material formed solely of Fe16P2. In other examples, the bulk magnetic material substantially includes only hard magnetic domains.

[0070] The bulk permanent magnetic material may be isotropic or anisotropic. In examples in which the Fe16P2 is isotropic, the energy product (proportional to the product of remanent coercivity and remanent magnetization) may be at least about 20 MGOe, or at least about 30 MGOe. In examples in which the Fe16P2 is anisotropic, the energy product may be as high as about 100 MGOe.

[0071] The bulk permanent magnetic material may have any suitable size or shape. In some examples, a smallest dimension of the bulk permanent magnetic material is greater than about 100 nanometers, or greater than about 1 micrometer, or greater than about 10 micrometers. In some examples, the smallest dimension is greater than about 100 micrometers. The bulk permanent magnetic material may include an aggregate of permanent magnetic particles or powder. The aggregate may be provided any suitable shape, for example, spherical, spheroidal, cylindrical, cuboid, polygonal, or any other shape or combination thereof.

[0072] FIG. 4 illustrates a flowchart of a technique for making a ferrous hard magnet including Fe16P2. The technique of FIG. 4 may include sputtering from an iron source to form a layer including Fe over a substrate (100). The iron source may include between about 1 atomic percent (at. %) and about 10 at. % of P. In some examples, the technique further includes forming a phosphorus plasma to provide a source of P atoms (102). For example, the phosphorus plasma may be the sole source of P atoms, or a further source of P atoms in addition to P atoms in the iron source. The technique may further include annealing the layer (104). For example, the annealing may be performed at a temperature in a range from about 100° C to about 210° C for a time in a range from about 5 hours to about 100 hours. The technique may be performed in any suitable magnet fabrication unit or using any suitable magnet fabrication system.

[0073] While the technique of FIG. 4 is described with reference to a hard magnet, in other examples, a similar technique may be used to form a soft magnetic material. For example, the technique may include sputtering (100) from at least one of a C-doped, B-Docket No.: 1008-365WO01 / 2023-285 doped, Al-doped, Si-doped, S-doped, or O-doped iron source to form a layer including Fe, P, and at least one of C, B, Al, Si, S, or O over a substrate. The technique may further include one or both of the forming he phosphorus plasma (102) or annealing the layer (104).

[0074] In some examples, a technique for forming the magnetic material includes depositing the magnetic material over a substrate using at least one of chemical vapor deposition, molecular beam epitaxy, low temperature epitaxy, liquid phase epitaxy, atomic layer deposition, or ion implantation. Systems and techniques similar to those described elsewhere in the disclosure with reference to forming soft magnetic materials using at least one of chemical vapor deposition, molecular beam epitaxy, low temperature epitaxy, liquid phase epitaxy, atomic layer deposition, or ion implantation may be used to form hard magnetic materials.

[0075] In some examples, a technique for forming a magnetic material includes straining, phosphorizing, and annealing an iron workpiece. For example, the technique may include straining an iron workpiece including at least one iron crystal in a direction substantially parallel to a <001> crystal axis of the iron crystal. The technique may further include phosphorizing the iron workpiece to form a phosphorized iron wire or sheet. The technique may further include annealing the phosphorized iron workpiece to form the magnetic material. Systems and techniques similar to those described elsewhere in the disclosure with reference to forming soft magnetic materials using straining and annealing may be used to form hard magnetic materials.

[0076] In some examples, a technique for forming a magnetic material includes ion implantation. For example, the technique may include implanting P atoms in an iron workpiece using ion implantation. The technique may further include pre-annealing the iron workpiece to attach the iron workpiece to a substrate. The technique may further include annealing the iron workpiece to form the magnetic material. Systems and techniques similar to those described elsewhere in the disclosure with reference to forming soft magnetic materials using ion implantation may be used to form hard magnetic materials.

[0077] In some examples, a technique for forming a magnetic material includes vapor deposition. For example, the technique may include heating an iron source to form a vapor including an Fe-containing compound. The technique may further include depositing Fe from the vapor including the Fe-containing compound and P from a vapor including a P- containing compound to form a layer including Fe and P. The technique may further include annealing the layer including Fe and P to form the magnetic material. Systems andDocket No.: 1008-365WO01 / 2023-285 techniques similar to those described elsewhere in the disclosure with reference to forming soft magnetic materials using vapor deposition may be used to form hard magnetic materials.

[0078] In some examples, a technique for forming a magnetic material includes liquid deposition. For example, the technique may include submerging a substrate in a coating solution including a P-containing solvent and an Fe source. The coating solution may be saturated with the Fe source at a first temperature above a liquidus temperature of an Fe-P mixture to be deposited from the coating solution. The technique may further include cooling the coating solution to a second temperature to form a supersaturated coating solution. The second temperature is below the liquidus temperature of the Fe-P mixture. The technique may further include maintaining the substrate in the supersaturated coating solution to allow a coating including Fe and P to form over the substrate. The technique may further include annealing the coating including Fe and P to form the magnetic material. Systems and techniques similar to those described elsewhere in the disclosure with reference to forming soft magnetic materials using liquid deposition may be used to form hard magnetic materials.

[0079] In some examples, a technique for forming a magnetic material includes milling. For example, the technique may include milling, in a bin of a milling apparatus, an Fe- containing raw material in the presence of a P source to generate a powder including Fe and P. The technique may further include annealing the powder to form the magnetic material. Systems and techniques similar to those described elsewhere in the disclosure with reference to forming soft magnetic materials using milling may be used to form hard magnetic materials.

[0080] In some examples, a technique for forming a magnetic material includes melt solidification. For example, the technique may include heating a mixture including iron and phosphorus to form a molten iron phosphorus-containing material. The technique may further include solidifying the molten iron phosphorus-containing material to form a workpiece including at least one Fe16P2phase domain. Systems and techniques similar to those described elsewhere in the disclosure with reference to forming soft magnetic materials using melt solidification may be used to form hard magnetic materials.

[0081] In some examples, a technique for forming a magnetic material includes melt spinning. For example, the technique may include forming a molten mixture including Fe. The technique may further include melt spinning the molten mixture including Fe to form Fe ribbons. The technique may further include phosphorizing the iron-carbon ribbons to form an Fe-P material.Docket No.: 1008-365WO01 / 2023-285

[0082] In some examples, the melt spinning technique may include forming a molten mixture including Fe. The technique may further include melt spinning the molten mixture including Fe to form Fe ribbons. The technique may further include ball milling the Fe ribbons to form Fe powder. The technique may further include phosphorizing the Fe powder. Systems and techniques similar to those described elsewhere in the disclosure with reference to forming soft magnetic materials using melt spinning may be used to form hard magnetic materials.

[0083] Magnetic materials formed using any technique according to the present disclosure may be further processed. For example, a technique may further include a plurality of the magnetic materials to form a bulk magnetic material.

[0084] In some examples, a technique for forming a magnetic material includes compacting nanoparticles including Fe16(PxZ1-x)2. Fe16(PxZ1-x)2 nanoparticles may be formed by either a chemical reaction or a milling process. For example, a composition including Fe may be treated in the presence of a P source to generate nanoparticles including Fe and P by a chemical reaction process. An average maximum major dimension of the nanoparticles may be in a range of 5 nm to 100 nm. An average short axis dimension of the nanoparticles may be in a range of 5 nm to 20 nm. An average long axis dimension of the nanoparticles may be in a range of 10 nm to 100 nm. The technique may further include annealing the compacted material. Systems and techniques similar to those described elsewhere in the disclosure with reference to forming soft magnetic materials using such a nanoparticle-based approach may be used to form hard magnetic materials.

[0085] In some examples, a technique for forming a magnetic material includes magnetic annealing. For example, the technique may include annealing a material including Fe and P in the presence of an applied magnetic field.

[0086] In some examples, a magnetic annealing technique may include phosphorizing a material including Fe in the presence of an applied magnetic field to form an Fe-P-containing material, and annealing the Fe-P-containing material in the presence of the applied magnetic field. The applied magnetic field may have a strength of at least about 0.2 Tesla (T).

[0087] In some examples, as described above, a magnet forming system may be configured to form the magnetic material. Examples of the magnet forming system include systems that form the soft magnetic material using at least one of casting, melt spinning, physical vapor deposition (PVD), sputtering, chemical vapor deposition (CVD), molecular beam epitaxy, low temperature epitaxy, liquid phase epitaxy, chemical reaction, atomic layer deposition, or ion implantation.Docket No.: 1008-365WO01 / 2023-285

[0088] FIG. 5 LV^D^FRQFHSWXDO^GLDJUDP^LOOXVWUDWLQJ^D^SHUVSHFWLYH^YLHZ^RI^DQ^ĮƎ-Fe16X2 unit cell, where X = P, C, B, Al, Si, S, or O. As shown in FIG. 5^^LQ^WKH^ĮƎ-Fe16X2 phase, the X atoms are aligned along the (002) (iron) crystal planes. The X atoms may include at least one of P, C, B, Al, Si, S, or O. When all the X atoms are P atoms, the resulting Fe-P unit cell may be the same as the unit cell described with reference to FIGS.1A and 1B.

[0089] Similarly, when X includes at least one of C, B, Al, Si, S, or O (Z atoms), ĮƎ- Fe16Z2may be a hard magnetic material when the Z atoms are ordered within the iron crystal lattice. 6LPLODU^WR^ĮƎ-Fe16P2, the Z atoms (C, B, Al, Si, S, RU^2^^LQ^RUGHUHG^ĮƎ-Fe16Z2 may be positioned at interstitial sites within the iron crystal. +RZHYHU^^LQ^RUGHUHG^ĮƎ-Fe16Z2, the ODWWLFH^SDUDPHWHUV^PD\^EH^GLIIHUHQW^WKDQ^WKH^ODWWLFH^SDUDPHWHUV^RI^ĮƎ-Fe16P2. For example, the presence of carbon atoms may be expected to reduce the distance between the C atoms and the surrounding Fe atoms lying in the (002) (iron) crystal planes from 3.74 Angstroms to 3.68 Angstroms. This is expected to increase p-d mixing, which is expected to increase bandwidth and lower the density of states. This is expected to reduce the magnetocrystalline anisotropy RI^ĮƎ-Fe16C2 to a negative value. Similar results may be expected for B and O atoms.

[0090] 2UGHUHG^ĮƎ-Fe16Z2, such as when Z is carbon (C), may exhibit magnetocrystalline anisotropy with a magnetic easy axis lying in the a-b plane (e.g.,

[0100] ; perpendicular to the c-axis). +HQFH^^WKH^GLUHFWLRQ^RI^PDJQHWRFU\VWDOOLQH^DQLVRWURS\^LQ^ĮƎ-Fe16Z2 may be VXEVWDQWLDOO\^SHUSHQGLFXODU^WR^WKH^GLUHFWLRQ^RI^PDJQHWRFU\VWDOOLQH^DQLVRWURS\^LQ^ĮƎ-Fe16N2. &DOFXODWLRQV^VKRZ^WKDW^WKH^PDJQHWRFU\VWDOOLQH^DQLVRWURS\^LQ^RUGHUHG^ĮƎ-Fe16C2may be about í^^^î^^7erg / cm3. ĮƎ-Fe16C2 also has a relatively high theoretical magnetic saturation PRPHQW^RI^DERXW^^^^^B / Fe.

[0091] +HQFH^^ZKHQ^RUGHUHG^ĮƎ-Fe16C2is mixed in SUHGHWHUPLQHG^TXDQWLWLHV^ZLWK^ĮƎ- Fe16P2 with c-D[HV^RI^WKH^UHVSHFWLYH^ĮƎ-Fe16C2 DQG^ĮƎ-Fe16P2 crystals oriented in substantially WKH^VDPH^GLUHFWLRQ^^WKH^PDJQHWRFU\VWDOOLQH^DQLVRWURSLHV^RI^ĮƎ-Fe16C2DQG^ĮƎ-Fe16P2may substantially cancel. Such cancelation may result in a material with a magnetocrystalline DQLVRWURS\^YDOXH^RI^QHDU^]HUR^^GHSHQGLQJ^RQ^WKH^YROXPH^UDWLR^RI^ĮƎ-Fe16C2 WR^ĮƎ-Fe16P2), while providing a theoretical magnetic saturation moment of, for example^^DERXW^^^^^B / Fe (the average of the WKHRUHWLFDO^PDJQHWLF^VDWXUDWLRQ^PRPHQWV^RI^ĮƎ-Fe16P2DQG^ĮƎ-Fe16C2). For H[DPSOH^^D^PDJQHWLF^PDWHULDO^LQFOXGLQJ^D^YROXPH^UDWLR^RI^ĮƎ-Fe16P2 WR^ĮƎ-Fe16C2 of about 4.667:5.333 may have a magnetic anisotropy of about 0 and a theoretical magnetic saturation moment in a range from about 2.0 to about 2.8 ^B / Fe. In this way, a mixture of SUHGHWHUPLQHG^YROXPHV^RI^ĮƎ-Fe16P2 GRPDLQV^DQG^ĮƎ-Fe16C2 domains may produce a magnetic material with a magnetocrystalline anisotropy value of near zero and a relativelyDocket No.: 1008-365WO01 / 2023-285 high magnetic saturation moment. Similar results may be expected when B, O, or both are substituted for C, based on the similar atomic radii of C, B, and O.

[0092] In some examples, the resulting material may be similar to that shown in FIG.6. FIG. 6 is a conceptual diagram illustrating a soft magnetic material 200 including domains of ĮƎ-Fe16P2 ^^^^DQG^GRPDLQV^RI^ĮƎ-Fe16Z2204, where Z = C, B, Al, Si, S, or O. In some examples, discrete domains of ĮƎ-Fe16P2202 may be present, along with discrete domains of ĮƎ-Fe16Z2204. The easy axes of the domains of ĮƎ-Fe16P2202 are illustrated as being oriented substantially vertically in FIG. 6, while the easy axes of the domains of ĮƎ-Fe16Z2 domains are illustrated as being oriented substantially horizontally in FIG. 6. When domains of ĮƎ-Fe16P2202 and domains of ĮƎ-Fe16Z2204 are present in predetermined volumes (e.g., about 4.667:5.333), this may lead the magnetocrystalline anisotropy of similar magnitudes and opposite signs to annihilate each other, resulting in a magnetic material 200 with high saturation magnetization and low magnetocrystalline anisotropy.

[0093] ,Q^RWKHU^H[DPSOHV^^UDWKHU^WKDQ^DOO^RI^WKH^UHVSHFWLYH^GRPDLQV^RI^ĮƎ-Fe16P2202 having their magnetic easy axes lying in substantially the same direction, the respective easy D[HV^RI^WKH^UHVSHFWLYH^GRPDLQV^RI^ĮƎ-Fe16P2202 may be substantially randomly distributed. 6LPLODUO\^^WKH^UHVSHFWLYH^HDV\^D[HV^RI^WKH^UHVSHFWLYH^GRPDLQV^RI^ĮƎ-Fe16Z2204 may be substantially randomly distributed. This also may lead to a magnetic material 200 with high saturation magnetization and low magnetocrystalline anisotropy.

[0094] In some examples, magnetic material 200 LQFOXGLQJ^D^PL[WXUH^RI^GRPDLQV^RI^ĮƎ- Fe16P2202 DQG^GRPDLQV^RI^ĮƎ-Fe16Z2204 PD\^QRW^LQFOXGH^RQO\^GRPDLQV^RI^ĮƎ-Fe16P2202 and GRPDLQV^RI^ĮƎ-Fe16Z2204. For example, magnetic material 200 may include at least one Fe16(PxZ1-x)2SKDVH^GRPDLQ^LQ^DGGLWLRQ^WR^GRPDLQV^RI^ĮƎ-Fe16P2202 DQG^GRPDLQV^RI^ĮƎ-Fe16Z2204. The size of the domains may be between about 1 nm and about 100 micrometers. The average domain size distribution may influence the permeability of the material as evidenced by the slope of the hysteresis loop. In some examples, magnetic material 200 including a PL[WXUH^RI^GRPDLQV^RI^ĮƎ-Fe16P2202 DQG^GRPDLQV^RI^ĮƎ-Fe16Z2204 may include other Fe phases, other Fe—P phases, other Fe-C phases, or other phases including other constituents (e.g., dopants, phase stabilizers, or impurities) present in the magnetic material.

[0095] In some examples, the structure shown in FIG. 6 may be formed by annealing a material including a mixture of Fe, C, and P in selected ratios to convert the mixture of Fe, C, and P WR^GRPDLQV^RI^ĮƎ-Fe16P2202 DQG^GRPDLQV^RI^ĮƎ-Fe16Z2204. In other examples, the structure shown in FIG. 6 PD\^EH^IRUPHG^E\^ILUVW^IRUPLQJ^SDUWLFOHV^LQFOXGLQJ^ĮƎ-Fe16P2 and SDUWLFOHV^LQFOXGLQJ^ĮƎ-Fe16Z2 (e.g., using milling), then consolidating the particles to form theDocket No.: 1008-365WO01 / 2023-285 PDWHULDO^LQFOXGLQJ^GRPDLQV^RI^ĮƎ-Fe16N2202 DQG^GRPDLQV^RI^ĮƎ-Fe16Z2204. Further details regarding example techniques for forming the material illustrated in FIG. 6 will be described below.

[0096] ,Q^VRPH^H[DPSOHV^^UDWKHU^WKDQ^LQFOXGLQJ^GLVFUHWH^GRPDLQV^RI^ĮƎ-Fe16P2DQG^ĮƎ- Fe16Z2, a material may LQFOXGH^RQH^RU^PRUH^FU\VWDOV^RI^ĮƎ-Fe16(PxZ1-x)2, where Z includes at least one of C, B, Al, Si, S or O, and x is a number greater than 0 and less than 1. In these examples, rather than forming discrete domains, the Fe, P, and Z atoms form a crystalline structure in which some interstitial locations are filled by P atoms and some interstitial locations are filled by Z atoms. For example, FIG. 5 LOOXVWUDWHV^DQ^H[DPSOH^ĮƎ-Fe16X2 unit cell, as described above. The unit cell in FIG. 5 illustrates five X atoms (1 X atom is fully in the unit cell, and 4 X atoms are partially in the unit cell). ,Q^ĮƎ-Fe16(PxZ1-x)2 at least some of the X atoms may be P atoms, and at least some of the X atoms may be Z (C, B, Al, Si, S, or O) atoms. $OWKRXJK^ĮƎ-Fe16(PxZ1-x)2may not include some P atoms and some Z atoms in each unit cell (e.g., some unit cells may include only P atoms and some unit cells may include only Z atoms), when averaged over the volume of the soft magnetic material, the ratio of Fe to P to Z atoms may be expressed by the chemical formula Fe16(PxZ1-x)2, where x is greater than 0 and less than 1. In some examples, X may be about 0.5 or about 0.4667.

[0097] In some examples, the magnetic material including Fe16(PxZ1-x)2 may not include only Fe16(PxZ1-x)2. )RU^H[DPSOH^^WKH^PDJQHWLF^PDWHULDO^PD\^LQFOXGH^DW^OHDVW^RQH^ĮƎ-Fe16P2SKDVH^GRPDLQ^RU^DW^OHDVW^RQH^ĮƎ-Fe16Z2domain in addition to at least one Fe16(PxZ1-x)2phase domain. In some examples, the magnetic material including Fe16(PxZ1-x)2 may include other Fe phases, other Fe-P phases, other iron carbide phases, or other phase including other constituents (e.g., dopants or impurities) present in the magnetic material.

[0098] ,Q^VRPH^H[DPSOHV^^D^PDJQHWLF^PDWHULDO^LQFOXGLQJ^DW^OHDVW^RQH^ĮƎ-Fe16(PxZ1-x)2 SKDVH^GRPDLQ^PD\^LQFOXGH^DW^OHDVW^DERXW^^^^YROXPH^SHUFHQW^ĮƎ-Fe16(PxZ1-x)2phase domain(s). In other examples, the magnetic material may include at least about 40 volume percent, at OHDVW^DERXW^^^^YROXPH^SHUFHQW^^RU^DW^OHDVW^DERXW^^^^YROXPH^SHUFHQW^ĮƎ-Fe16(PxZ1-x)2 phase domain(s). Similarly, D^PDJQHWLF^PDWHULDO^LQFOXGLQJ^D^PL[WXUH^RI^ĮƎ-Fe16P2 DQG^ĮƎ-Fe16Z2 PD\^LQFOXGH^DW^OHDVW^DERXW^^^^YROXPH^SHUFHQW^RI^WKH^FRPELQDWLRQ^RI^ĮƎ-Fe16P2DQG^ĮƎ-Fe16Z2phase domains. In other examples, the magnetic material may include at least about 40 volume percent, at least about 50 volume percent, or at least about 60 volume percent of the FRPELQDWLRQ^RI^ĮƎ-Fe16P2DQG^ĮƎ-Fe16Z2phase domains.

[0099] In some examples, the magnetic material including Fe16(PxZ1-x)2 or a mixture of ĮƎ-Fe16P2 DQG^ĮƎ-Fe16Z2 may have a saturation magnetization of at least about 180 emu / gram,Docket No.: 1008-365WO01 / 2023-285 or at least 219 emu / gram, which is the saturation magnetization of pure iron. In some examples, the magnetic material including Fe16(PxZ1-x)2 RU^D^PL[WXUH^RI^ĮƎ-Fe16P2 DQG^ĮƎ- Fe16Z2may have a saturation magnetization of at least about 242 emu / gram, which is the saturation magnetization of Fe65Co35. In some examples, the magnetic material including Fe16(PxZ1-x)2 RU^D^PL[WXUH^RI^ĮƎ-Fe16P2 and ĮƎ-Fe16Z2 may have a saturation magnetization of at least about 250 emu / gram.

[0100] In some examples, the magnetic material including Fe16(PxZ1-x)2or a mixture of ĮƎ-Fe16P2 DQG^ĮƎ-Fe16Z2 may have a magnetic coercivity of less than or equal to about 10 Oe. IQ^VRPH^H[DPSOHV^^WKH^PDJQHWLF^PDWHULDO^LQFOXGLQJ^ĮƎ-Fe16(PxZ1-x)2 RU^D^PL[WXUH^RI^ĮƎ-Fe16P2 DQG^ĮƎ-Fe16Z2also may possess high magnetic permeability, high frequency response, or the like.

[0101] In some examples, a soft magnetic material includes at least one of DQ^Į^-Fe16(PxZ1-x)2 GRPDLQ^RU^DQ^Įƍ-Fe8(PxZ1-x) phase domain, wherein Z includes at least one of C, B, Al, Si, S, or O, and wherein x is a number greater than zero and less than one. In some examples, x is equal to about 0.5. In some such examples, x is equal to 0.5. In some examples, Z consists essentially of, or consists, of C. In some such examples, the phase domain essentially consists of, or consists of, Į´- Fe16PC.

[0102] The at least one of the Į^-Fe16(PxZ1-x)2 SKDVH^GRPDLQ^RU^WKH^Įƍ-Fe8(PxZ1-x) phase domain may include D^SOXUDOLW\^RI^DW^OHDVW^RQH^RI^Į^-Fe16(PxZ1-x)2FU\VWDOV^RU^Įƍ-Fe8(PxZ1-x) crystals, where respective

[0001] axes of the plurality of crystals are randomly distributed within the soft magnetic material. In some examples, the soft magnetic material may further include DW^OHDVW^RQH^RI^DQ^ĮƎ-Fe16P2SKDVH^GRPDLQ^^DQ^ĮƎ-Fe16Z2SKDVH^GRPDLQ^^DQ^Įƍ-Fe8P SKDVH^GRPDLQ^^RU^DQ^Įƍ-Fe8Z phase domain. In some examples, tKH^Į^-Fe16(PxZ1-x)2phase domain includes body centered tetragonal (BCT) unit cells.

[0103] In some examples, at least about 35 volume percent of the soft magnetic material is WKH^DW^OHDVW^RQH^RI^WKH^ĮƎ-Fe16(PxZ1-x)2SKDVH^GRPDLQ^RU^WKH^Įƍ-Fe8(NxZ1-x) phase domain. In some examples, at least about 60 volume percent of the soft magnetic material is the at least RQH^RI^WKH^ĮƎ-Fe16(PxZ1-x)2 SKDVH^GRPDLQ^RU^WKH^Įƍ-Fe8(NxZ1-x) phase domain.

[0104] In some examples, a soft magnetic material includes a phospho-carbon-ferrous domain including a plurality of Fe6P clusters and a plurality of Fe6C clusters. The Fe6C clusters may be similar to Fe6P clusters described with reference to FIGS. 2A and 2B. Alternatively, C atoms may be dispersed in a lattice of Fe6P clusters. Each cluster of the plurality of Fe6P clusters may include P at a geometric center of a respective octahedralDocket No.: 1008-365WO01 / 2023-285 arrangement of Fe. Likewise, each cluster of the plurality of Fe6C clusters may include C at a geometric center of a respective octahedral arrangement of Fe.

[0105] The soft magnetic material may be free of any rare-earth element, for example, being free of neodymium (Nd).

[0106] The soft magnetic material may further include a dopant. In some examples, the dopant includes at least one of Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, Pt, Au, Sm, C, Pb, W, Ga, Y, Mg, Hf, Ge, Al, or Ta.

[0107] The soft magnetic material may further include a phase stabilizer. In some examples, the phase stabilizer includes at least one of B, Al, C, Si, O, Co, Cr, Mn, Ti, V, or S.

[0108] The present disclosure describes techniques for forming a magnetic material according to the present disclosure, for example, a soft magnetic material including a Fe-P phase domain, a including Fe16(PxZ1-x)2, RU^D^PL[WXUH^RI^ĮƎ-Fe16P2 DQG^ĮƎ-Fe16Z2.

[0109] In some examples, as described above, a magnet forming system may be configured to form the soft magnetic material. Examples of the magnet forming system include systems that form the soft magnetic material using at least one of casting, melt spinning, sputtering, chemical vapor deposition (CVD), molecular beam epitaxy, low temperature epitaxy, liquid phase epitaxy, or ion implantation.

[0110] FIG. 7 is a conceptual and schematic diagram illustrating an example CVD system 300 IRU^IRUPLQJ^D^PDJQHWLF^PDWHULDO^LQFOXGLQJ^ĮƎ-Fe16(PxZ1-x)2RU^D^PL[WXUH^RI^ĮƎ- Fe16P2DQG^ĮƎ-Fe16Z2, where Z includes at least one of C, B, Al, Si, S, or O. CVD system 300 is an example of the magnet forming system. CVD system 300 may be used to form a coating including Fe, P, and at least one of C, B, Al, Si, S, or O, which then may be annealed WR^IRUP^D^PDJQHWLF^PDWHULDO^LQFOXGLQJ^ĮƎ-Fe16(PxZ1-x)2RU^D^PL[WXUH^RI^ĮƎ-Fe16P2DQG^ĮƎ- Fe16Z2.

[0111] System 300 includes a CVD chamber 322, which may enclose a susceptor 324. A substrate 326 is held by susceptor 324, and coating 328 is formed over at least a portion of substrate 26. CVD chamber 322 may include, for example, quartz or another refractory material. In some examples, CVD chamber 322 may be formed of a material that is substantially transparent to radio frequency (RF) magnetic energy.

[0112] In some examples, CVD chamber 322 is at least partially surrounded by RF induction coils 330. RF induction coils 330 may be electrically connected to an RF source (not shown in FIG. 7), which causes an alternating electrical current at RF to flow through RF induction coils 330. In some examples, the RF magnetic field generated by RF induction coils 330 may be absorbed by susceptor 324, which converts the RF energy to heat. ThisDocket No.: 1008-365WO01 / 2023-285 heats substrate 346. Hence, in some examples, susceptor 324 may include graphite or another material that absorbs RF energy of the frequency generated by RF induction coils 330.

[0113] In some examples, susceptor 324 may be shaped or oriented to position substrate 326 at an incline with respect to inlet 332. Positioning substrate 326 at an incline with respect to inlet 332 may reduce or substantially eliminate downstream depletion, which is a phenomenon in which downstream portions of substrate 346 are coated with a thinner coating than upstream portions of substrate 326 due to depletion of reactants from the coating gas as the coating gas flows along a substantially horizontal substrate 326.

[0114] In some examples, rather than including a susceptor 324 heated by RF induction coils 330, CVD chamber 322 may be heated such that an entire volume of CVD chamber 322 is heated. For example, CVD chamber 322 may be disposed in a furnace, or CVD chamber 322 may be formed of a material that absorbs RF energy and heats the volume of CVD chamber 322.

[0115] Substrate 326 may include any material on which coating 328 may be formed. For example, substrate 326 may include a semiconductor, such as silicon, GaAs, InGaAs, or the like. In other examples, the substrate may include another material, such as a glass; a high temperature polymer; SiC; MgO; SiO2 (e.g., a layer of SiO2 on a Si or other semiconductor substrate); a metal layer, such as Fe, Al, Cu; or the like.

[0116] In some examples, substrate 326 may include a crystalline material with a GLIIHUHQW^ODWWLFH^VWUXFWXUH^^GLIIHUHQW^ODWWLFH^SDUDPHWHUV^^RU^ERWK^^WKDQ^DW^OHDVW^RQH^RI^ĮƎ-Fe16P2, ĮƎ-Fe16Z2^^RU^ĮƎ-Fe16(PxZ1-x)2, where Z includes at least one of C, B, Al, Si, S, or O. In some examples, substrate 326 additionally or alternatively may have a different coefficient of WKHUPDO^H[SDQVLRQ^^&7(^^WKDQ^DW^OHDVW^RQH^RI^ĮƎ-Fe16P2^^ĮƎ-Fe16Z2^^RU^ĮƎ-Fe16(PxZ1-x)2. In examples in which substrate 326 includes at least one of a different lattice structure, different ODWWLFH^SDUDPHWHUV^^RU^D^GLIIHUHQW^&7(^WKDQ^DW^OHDVW^RQH^RI^ĮƎ-Fe16P2^^ĮƎ-Fe16Z2^^RU^ĮƎ- Fe16(PxZ1-x)2, substrate 326 may exert a strain on coating 328 during an annealing technique, ZKLFK^PD\^IDFLOLWDWH^IRUPDWLRQ^RI^DW^OHDVW^RQH^RI^ĮƎ-Fe16(PxZ1-x)2 RU^D^PL[WXUH^RI^ĮƎ-Fe16P2 DQG^ĮƎ-Fe16Z2in coating 328.

[0117] CVD chamber 322 may include an inlet 332 and an outlet 334. Inlet 332 may be fluidically connected to one or more sources of coating gases. For example, in system 300, inlet 332 is fluidically connected to a carrier gas source 336, a first source 340 of a coating constituent, and a second source 344 of a coating constituent, and a third source 348 of a coating constituent.Docket No.: 1008-365WO01 / 2023-285

[0118] In some examples, carrier gas source 336 may include a gas that carries the coating gas to the interior of CVD chamber 322. In some examples, carrier gas source 336 may include a source of substantially inert gas (e.g., a gas that is substantially non-reactive with other elements and compounds present in system 300 during operation of system 300). A substantially inert gas may include, for example, a noble gas, such as argon.

[0119] In some examples, carrier gas source 336 additionally or alternatively may include a gas that may react with one or more elements and compounds present in system 300. For examples, carrier gas source 336 may include a source of hydrogen gas (H2). In some examples, hydrogen gas may react with an Fe precursor to liberate Fe. In some instances, carrier gas source 336 may include a mixture of a substantially inert gas and a gas that reacts with one or more elements and compounds present in system 300. For example, carrier gas source 336 may include a mixture of hydrogen gas and argon.

[0120] Carrier gas source 336 may be fluidically connected to CVD chamber 322 via conduit or piping, and at least one valve 338. Valve 338 may be used to control flow of carrier gas from carrier gas source 336 to CVD chamber 322.

[0121] System 300 also includes first source 340. First source 340 may include a source of a vapor including a P-containing compound. In some examples, first source 340 may include a gaseous source of a P precursor. In other examples, first source 340 may include a liquid or solid source of a P precursor.

[0122] In examples in which the P-containing compound in first source 340 is a solid or liquid, first source 340 may include a heat source to vaporize the P-containing compound and form a vapor including a P-containing compound.

[0123] First source 340 may be fluidically connected to CVD chamber 322 via conduit or piping, and at least one valve 342. Valve 342 may be used to control flow of P-containing vapor from first source 340 to CVD chamber 322.

[0124] System 300 also includes second source 344. Second source 344 may include a source of a vapor including a Z atom-containing compound, where Z includes at least one of C, boron, or oxygen. For the purposes of description only, FIG. 7 will be described with second source 344 being a source of a C-containing compound. However, it will be appreciated that similar principles may be applied to sources of a boron-containing material, sources of an oxygen containing material, or both.

[0125] In some examples, second source 344 may include a gaseous source of a C- containing compound, such as gaseous carbon monoxide (CO), gaseous carbon dioxide (CO2), or gaseous methane (CH4). In other examples, second source 344 may include aDocket No.: 1008-365WO01 / 2023-285 liquid or solid source of a C-containing compound, such as pure C (e.g., graphite) or urea. In examples in which the C-containing compound in second source 344 is a solid or liquid, second source 344 may include a heat source to vaporize the C-containing compound and form a vapor including a C-containing compound.

[0126] Second source 344 may be fluidically connected to CVD chamber 322 via conduit or piping, and at least one valve 346. Valve 346 may be used to control flow of C- containing vapor from second source 344 to CVD chamber 322.

[0127] In some examples, such as when a single source is used both for the C source and the P source, system 300 may not include separate first and second sources 340 and 344 for the P-containing compound and the C-containing compound, but may instead include a single source for both the P-containing compound and the C-containing compound.

[0128] System 300 also includes third source 348. Third source 348 may include a source of Fe or an Fe precursor (or donor). In the example shown in FIG. 7, third source 348 contains a liquid Fe donor 350, such as FeCl3 or Fe(CO)5. Third source 348 is fluidically coupled to a gas source 352 via valve 354, which controls flow of gas from gas source 352 into third source 348. In some examples, gas source 352 may be a source of hydrogen (H2) has or another reducing gas.

[0129] Gas from gas source 352 flows into third source 348 and vaporizes at least some of liquid Fe donor 350. Gas from gas source 352 then carries the vapor including the Fe- containing compound into CVD chamber 322 through inlet 332.

[0130] Valves 338, 342, 346, and 354 may be used to control the total flow rate of gases and vapors into CVD chamber 322, and the relative proportion of carrier gas, the vapor including the P-containing compound, the vapor including the C-containing compound, and the vapor including the Fe-containing compound in the gases and vapors flowing into CVD chamber 22. For example, valves 338, 342, 346, and 354 may be controlled to allow the carrier gas, the vapor including the P-containing compound, the vapor including the C- containing compound, and the vapor including the Fe-containing compound to flow into CVD chamber 322 to produce a predetermined atomic ratio of Fe to the combination P and C in the gases and vapors flowing into CVD chamber.

[0131] Additionally, valves 342 and 346 may be controlled to control the relative flow rates of the vapor including the P-containing compound and the vapor including the C- containing compound to produce a predetermined atomic ratio of P to C in the gases flowing into CVD chamber 322. For example, valves 342 and 346 may be controlled to control the relative flow rates of the vapor including the P-containing compound and the vapor includingDocket No.: 1008-365WO01 / 2023-285 the C-containing compound to produce an atomic ratio of P to C of between about 0.1:1 and about 10:1, such as about 1:1 or about 4.667:5.333.

[0132] In some examples, valves 338, 342, 346, and 354 may be controlled to produce a flow rate of the carrier gas between about 5 standard cm3 / minute (sccm) and about 5,000 sccm, flow rate of the vapor including the P-containing compound between about 10 sccm and about 1,000 sccm, a flow rate of the vapor including the C-containing compound between about 0.1 sccm and about 1,000 sccm, and a flow rate of the vapor including the Fe- containing compound between about 100 sccm and about 5,000 sccm. Flow rates such as these may result in a growth rate of coating 328 of between about 100 micrometers per hour ^^P^K^^DQG^DERXW^^^^^^^^P^K^

[0133] In some examples, substrate 326 may be heated by susceptor 344 and RF induction coils 330 above at least one of a decomposition temperature of the Fe-containing compound, the decomposition temperature of the P-containing compound, or a decomposition temperature of the C-containing compound. For example, substrate 326 may be heated to a temperature between about 200° C and about 1,000° C by susceptor 324 and RF induction coils 330.

[0134] In some examples in which substantially only susceptor 324 and substrate 326 is heated, the Fe-containing compound, the P-containing compound, and the C-containing compound may decompose to release Fe, P, and C, or may react with each other to form an Fe-P-C compound. Because substrate 326 is heated, this reaction or reactions may occur at the surface of substrate 326, resulting in coating 328 being formed and including Fe, P, and C.

[0135] In examples in which substantially the entire volume of CVD chamber 322 is heated (e.g., by a furnace), the decomposition reactions or reaction between the Fe-containing compound, the P-containing compound, and the C-containing compound may occur above substrate within the volume of CVD chamber 322. The liberated Fe, C, and P atoms or Fe-C- P compound then may deposit over the surface of substrate 326 in coating 328.

[0136] In some examples, portions of substrate 326 may be masked, leaving only portions of substrate 326 exposed over which coating 328 is formed. In other examples, coating 328 may be etched after deposition of coating 328 to remove the portions of coating 328, leaving only portions of substrate 326 coated with coating 328. In this way, coating 328 may be controllably formed over only selected portions of substrate 326 and later converted to the magnetic material.Docket No.: 1008-365WO01 / 2023-285

[0137] Once coating 328 has been formed to a predetermined thickness, substrate 326 and coating 328 may be removed from CVD chamber 322 and subjected to an annealing technique.

[0138] The annealing technique may facilitate magnetic material including at least one RI^ĮƎ-Fe16(PxZ1-x)2 phase (where Z includes at least one of C, B, Al, Si, S, or O) or a mixture RI^ĮƎ-Fe16P2SKDVH^DQG^ĮƎ-Fe16Z2phase. The annealing technique may be carried out at a temperature that produces strain in coating 328 due to differences in the coefficients of thermal expansion for substrate 326 and coating 328 to access at least one of the mixture of ĮƎ-Fe16P2 SKDVH^DQG^ĮƎ-Fe16C2 SKDVH^RU^WKH^ĮƎ-Fe16(PxC1-x)2 phase.

[0139] Additionally, the annealing technique allows diffusion of P+ ions, C+ ions, or both within Fe crystals in coating 328 WR^IRUP^DW^OHDVW^RQH^RI^ĮƎ-Fe16P2^^ĮƎ-Fe16C2, or ĮƎ- Fe16(PxC1-x)2. In some examples, annealing at relatively low temperatures allows transformation of partial Fe8P GLVRUGHUHG^SKDVH^LQWR^ĮƎ-Fe16P2ordered phase. Similarly, annealing at relatively low temperatures is expected to allow transformation of partial Fe8C GLVRUGHUHG^SKDVH^LQWR^ĮƎ-Fe16C2 ordered phase and partial Fe8(PxC1-x) disordered phase into ĮƎ-Fe16(PxC1-x)2ordered phase.

[0140] In some examples, the annealing technique may be carried out at a temperature below about 300° C., such as between about 120° C and about 300° C, between about 120° C and about 220° C, or between about 150° C and about 220° C. The annealing technique may be performed in a nitrogen (N2) or argon (Ar) atmosphere, or in a vacuum or near-vacuum.

[0141] The temperature and duration of the annealing step may be selected based on, for example, a size of the sample and diffusion coefficient of P atoms in Fe and C atoms in Fe at the annealing temperature. Based on these factors, the temperature and duration may be selected to provide sufficient time for P atoms to diffuse to locations within coating 328 to form Fe16P2GRPDLQV^^ĮƎ-Fe16C2GRPDLQV^^DQG^RU^ĮƎ-Fe16(PxC1-x)2domains.

[0142] Additionally, the temperature and duration of the annealing technique may be selected based on a desired volume fraction of the respective phase domains in coating 328. For example, at a selected temperature, a longer annealing technique may result in a higher YROXPH^IUDFWLRQ^RI^ĮƎ-Fe16P2^^ĮƎ-Fe16C2^^DQG^RU^ĮƎ-Fe16(PxC1-x)2. Similarly, for a given annealing technique duration, a higher temperature may result in a higher volume fraction of ĮƎ-Fe16P2^^ĮƎ-Fe16C2^^DQG^RU^ĮƎ-Fe16(PxC1-x)2. However, for durations above a threshold YDOXH^^WKH^DGGLWLRQDO^YROXPH^IUDFWLRQ^RI^ĮƎ-Fe16P2^^ĮƎ-Fe16C2, DQG^RU^ĮƎ-Fe16(PxC1-x)2may be OLPLWHG^RU^HOLPLQDWHG^^DV^WKH^YROXPH^IUDFWLRQ^RI^ĮƎ-Fe16P2^^ĮƎ-Fe16C2^^DQG^RU^ĮƎ-Fe16(PxC1-x)2 reaches a relatively stable value. For example, at a temperature of about 150° C., after aboutDocket No.: 1008-365WO01 / 2023-285 ^^^KRXUV^^WKH^YROXPH^IUDFWLRQ^RI^ĮƎ-Fe16P2 reaches a stable value. The duration of the annealing step may be at least about 5 hours, such as at least about 20 hours, or between about 5 hours and about 100 hours, or between about 5 hours and about 80 hours or between about 20 hours and about 80 hours, or about 40 hours.

[0143] Fe8P DQG^ĮƎ-Fe16P2 have similar body-centered tetragonal (BCT) crystalline structure. +RZHYHU^^LQ^ĮƎ-Fe16P2, P atoms are ordered within the Fe lattice, while in Fe8P, P atoms are randomly distributed within the Fe lattice. The annealing technique facilitates formation of the BCT ĮƎ-Fe16P2 phase crystalline structure at least in part due to the strain exerted on the Fe crystal lattice as a result of differential expansion of substrate 326 and coating 328 during the annealing step.

[0144] For example, the coefficient of thermal expansion for Fe LV^^^^^^^P^Pā.^^ZKLOH^ IRU^VLOLFRQ^LW^LV^^^^^^P^Pā.^^ This difference in thermal expansion coefficients results in a compression stress substantially parallel the major plane of coating 328 and a corresponding stretching force being generated along the <001> crystalline direction on a coating 328 with an (110) face. In some examples, the strain on coating 328 may be between about 0.3% and about 7%, which may result in a substantially similar strain on individual crystals of the Fe-P, such that the unit cell is elongated along the <001> axis between about 0.3% and about 7%. This may facilitate incorporation of P DWRPV^DW^WKH^SUHIHUUHG^SRVLWLRQV^RI^WKH^ĮƎ-Fe16P2 crystal.

[0145] Similarly, C DWRPV^LQ^ĮƎ-Fe16C2and P and C DWRPV^LQ^ĮƎ-Fe16(PxC1-x)2may be aligned along the (002) (Fe) crystal planes. The annealing technique facilitates formation of the BCT ĮƎ-Fe16C2 SKDVH^FU\VWDOOLQH^VWUXFWXUH^RU^ĮƎ-Fe16(PxC1-x)2 in coating 328 at least in part due to the strain exerted on the Fe crystal lattice as a result of differential expansion of substrate 326 and coating 328 during the annealing step.

[0146] Although FIG. 7 illustrates an example system 300 for CVD using a liquid iron- containing material, in other examples, CVD may be performed using a solid iron-containing material.

[0147] FIG. 8 is a conceptual and schematic diagram illustrating an example CVD system 400 IRU^IRUPLQJ^D^PDJQHWLF^PDWHULDO^LQFOXGLQJ^ĮƎ-Fe16(PxZ1-x)2 RU^D^PL[WXUH^RI^ĮƎ- Fe16Z2DQG^ĮƎ-Fe16P2, where Z includes at least one of C, B, Al, Si, S, or O. CVD system 400 is an example of the magnet forming system. CVD system 400 may be used to form a coating including Fe, P, and at least one of C, B, Al, Si, S, or O, which then may be annealed WR^IRUP^D^PDJQHWLF^PDWHULDO^LQFOXGLQJ^ĮƎ-Fe16(PxZ1-x)2RU^D^PL[WXUH^RI^ĮƎ-Fe16P2DQG^ĮƎ- Fe16Z2.Docket No.: 1008-365WO01 / 2023-285

[0148] Similar to FIG. 7, FIG. 8 will be described with respect to examples where Z is C. However, it will be appreciated that similar principles may be applied to sources of a boron-containing material, sources of an oxygen containing material, or both. In some examples, system 400 of FIG. 8 may be similar to or substantially the same as system 300 described with reference to FIG.7, aside from the differences described herein.

[0149] System 400 includes a CVD chamber 462. CVD chamber 462 encloses a susceptor 464, which may be similar or substantially the same as susceptor 324 of FIG. 7. In the example illustrated in FIG. 8, susceptor 464 is not shaped or oriented to position substrate 326 at an incline with respect to inlets 466, 468, and 470. In other examples, susceptor 464 may be shaped or oriented to position substrate 326 at an incline with respect to inlets 466, 468, and 470. CVD chamber 462 may include, for example, quartz or another refractory material. In some examples, CVD chamber 462 may be formed of a material that is substantially transparent to radio frequency (RF) magnetic energy.

[0150] CVD chamber 462 is at least partially surrounded by RF induction coils 330. RF induction coils 330 may be similar to or substantially the same as RF induction coils 330 illustrated in FIG. 7. CVD chamber 462 encloses substrate 326, over which coating 328 is formed. Substrate 326 is disposed on susceptor 464.

[0151] In some examples, rather than including a susceptor 464 heated by RF induction coils 330, CVD chamber 462 may be heated such that an entire volume of CVD chamber 462 is heated. For example, CVD chamber 462 may be disposed in a furnace, or CVD chamber 462 may be formed of a material that absorbs RF energy and heats the volume of CVD chamber 462.

[0152] CVD chamber 462 may include inlets 466, 468, and 470 and an outlet 334. Inlets 466, 468, and 470 may be fluidically connected to one or more sources of coating gases. For example, in system 400, inlet 466 is fluidically connected to a chamber 72 enclosing a solid Fe-containing material 474, inlet 468 is fluidically coupled to a first source 340 of a coating constituent via a valve 342, and inlet 470 is fluidically coupled to a second source 344 of a coating constituent via a valve 46. First source 340, valve 342, second source 344, and valve 346 may be similar to or substantially the same as described above with respect to FIG. 7. For example, first source 340 may include a source of a vapor including a P-containing compound and second source 344 may include a source of a vapor including a C-containing compound (more generally, a source of a vapor including at least one of a C-containing compound, a boron-containing compound, or an oxygen-containing compound).Docket No.: 1008-365WO01 / 2023-285

[0153] Chamber 472 encloses a solid Fe-containing material 474. In some examples, Fe- containing material 474 may include an Fe-containing powder, billet, or thin film deposited on a substrate. In some examples, Fe-containing material 474 includes substantially pure Fe (e.g., Fe with a purity of greater than 90 at. %). In other examples, Fe-containing material 474 may include Fe oxide (e.g., Fe2O3 or Fe3O4).

[0154] Chamber 472 may include a first inlet 476 and a second inlet 478. First inlet 476 may be fluidically connected to a first gas source 480 by a valve 482. First gas source 480 may include a source of an acid or chloride, such as HCl. The acid or chloride may react with Fe-containing material 474 to form an Fe-containing vapor. For example, HCl may react with Fe-containing material 474 to form iron chloride (FeCl3), which may be heated to form a vapor.

[0155] Second inlet 478 may be fluidically coupled to a carrier gas source 484 by a valve 486. In some examples, carrier gas source 484 may include a source of substantially inert gas (e.g., a gas that is substantially non-reactive with other elements and compounds present in system 400 during operation of system 400). A substantially inert gas may include, for example, a noble gas, such as argon.

[0156] Valves 342, 346, 482, and 486 may be used to control the total flow rate of gases and vapors into CVD chamber 462, and the relative proportion of carrier gas, P-containing vapor, C-containing vapor, and Fe-containing vapor in the gases and vapors flowing into CVD chamber 462. For example, valves 342, 346, 482, and 486 may be controlled to allow deposition of coating 328, which includes Fe, C, and P, and as described with respect to FIG. 7.

[0157] In some examples, to form coating 328, valves 342, 346, 482, and 486 may be controlled to allow the carrier gas, the vapor including the P-containing compound, the vapor including the C-containing compound, and the vapor including the Fe-containing compound to flow into CVD chamber 462 to produce a predetermined atomic ratio of Fe to the combination P and C in the gases and vapors flowing into CVD chamber 462.

[0158] Additionally, valves 342 and 346 may be controlled to control the relative flow rates of the vapor including the P-containing compound and the vapor including the C- containing compound to produce a predetermined atomic ratio of P to C in the gases flowing into CVD chamber 462. For example, valves 342 and 346 may be controlled to control the relative flow rates of the vapor including the P-containing compound and the vapor including the C-containing compound to produce an atomic ratio of P to C of between about 0.1:1 and about 10:1, such as about 1:1 or about 4.4667:5.333.Docket No.: 1008-365WO01 / 2023-285

[0159] In some examples, to form coating 328, the flow rate of the carrier gas may be between about 5 sccm and about 5,000 sccm, the flow rate of the vapor including the P- containing compound may be between about 10 sccm and about 1,000 sccm, the flow rate of the vapor including the C-containing compound may be between about 0.1 sccm and about 1,000 sccm, and the flow rate of the vapor including the Fe-containing compound may be between about 100 sccm and about 5,000 sccm. Flow rates such as these may result in a growth rate of coating 328 RI^EHWZHHQ^DERXW^^^^^^P^K^DQG^DERXW^^^^^^^^P^K^

[0160] In some examples, the HCl may react with Fe in chamber 472 according to the following reaction: )H^+&Oĺ)H&O3+H2. The FeCl3 and H2 may flow into CVD chamber 462 through first inlet 466, where the vapors may mix with a P-containing vapor.

[0161] As described above with respect to FIG. 7, once coating 328 has been formed to a predetermined thickness, coating 328 may be annealed to transform at least some of the Fe, C, and P mixture coating 328 WR^DW^OHDVW^RQH^RI^ĮƎ-Fe16(PxC1-x)2RU^D^PL[WXUH^RI^ĮƎ-Fe16P2and ĮƎ-Fe16C2. The annealing technique may be similar to or substantially the same as that described above with respect to FIG. 7.

[0162] By using CVD to form coating 328 over substrate 326, magnetic material LQFOXGLQJ^DW^OHDVW^RQH^RI^ĮƎ-Fe16(PxC1-x)2 RU^D^PL[WXUH^RI^ĮƎ-Fe16P2 DQG^ĮƎ-Fe16C2 may be incorporated into other products formed using CVD and existing manufacturing techniques that utilize CVD. Using existing CVD manufacturing operations, including masking, PDJQHWLF^PDWHULDO^LQFOXGLQJ^DW^OHDVW^RQH^RI^ĮƎ-Fe16(PxC1-x)2RU^D^PL[WXUH^RI^ĮƎ-Fe16P2DQG^ĮƎ- Fe16C2 may be deposited over predetermined portions or regions of substrate 326. For H[DPSOH^^PDJQHWLF^PDWHULDOV^LQFOXGLQJ^DW^OHDVW^RQH^RI^ĮƎ-Fe16(PxC1-x)2RU^D^PL[WXUH^RI^ĮƎ- Fe16P2DQG^ĮƎ-Fe16C2may be incorporated into CMOS (complementary metal-oxide- semiconductor) integrated circuit devices, and the CVD technique for forming magnetic PDWHULDOV^LQFOXGLQJ^DW^OHDVW^RQH^RI^ĮƎ-Fe16(PxC1-x)2RU^D^PL[WXUH^RI^ĮƎ-Fe16P2DQG^ĮƎ-Fe16C2may be incorporated into existing CMOS processing techniques. In other examples, magnetic PDWHULDOV^LQFOXGLQJ^DW^OHDVW^RQH^RI^ĮƎ-Fe16(PxC1-x)2 or a mixture of ĮƎ-Fe16P2 DQG^ĮƎ-Fe16C2 formed using CVD may be incorporated into other devices utilizing magnetic materials.

[0163] CVD may allow growth of coating 328 faster than some other techniques, such as molecular beam epitaxy (MBE), while, in some examples, forming superior coatings compared to some other techniques, such as sputtering.Docket No.: 1008-365WO01 / 2023-285

[0164] Thus, an example vapor deposition technique for forming a soft magnetic material includes heating an iron source to form a vapor including an Fe-containing compound. The technique may further include depositing Fe from the vapor including the Fe-containing compound, P from a vapor including a P-containing compound, and at least one of C, B, Al, Si, S, or O from a vapor including the compound containing the at least one of C, B, Al, Si, S, or O over a substrate to form a layer including Fe, P, and the at least one of C, B, Al, Si, S, or O. The technique may further include annealing the layer including Fe, P, and the at least one of C, B, Al, Si, S, or O to form the soft magnetic material.

[0165] In some examples, an example vapor deposition technique includes heating an iron source to form a vapor including an Fe-containing compound. The technique may further include depositing Fe from the vapor including the Fe-containing compound and P from a vapor including a P-containing compound over a substrate to form a first layer including Fe and P. The technique may further include heating an iron source to form a vapor including an Fe-containing compound. The technique may further include depositing iron from the vapor including the Fe-containing compound and at least one of C, B, Al, Si, S, or O from a vapor including the at least one of C, B, Al, Si, S, or O over the substrate to form a second layer including iron and the at least one of C, B, Al, Si, S, or O. The technique may further include annealing the first layer and the second layer to form the soft magnetic material.

[0166] The example vapor deposition techniques may be performed using system 300 or system 400 described with reference to FIGS. 7 and 8, or any other suitable system.

[0167] In other examples, a coating (e.g., coating 328) may be formed over a substrate (e.g., substrate 326) using liquid phase epitaxy (LPE). In LPE, a solution including the coating materials may be cooled to form a supersaturated solution. The coating materials in the solution deposit a coating over a substrate immersed or submerged in the solution. In some examples, the degree of supersaturation may be low, such that the LPE technique is a near-equilibrium process. This may result in coatings with high crystalline quality (e.g., near-perfect crystalline structure). Additionally, because the concentration of the coating materials in the solution are much greater than the concentration of coating materials in vapor phase techniques, the growth rate of the coating may be greater than the growth rate for coatings grown using vapor phase techniques.

[0168] FIG. 9 is a conceptual and schematic diagram illustrating an example system 500 for forming a coating including Fe, P, and C over a substrate 326 using LPE. System 500 includes a crucible 502 in which a coating solution 506 is contained. System 500 alsoDocket No.: 1008-365WO01 / 2023-285 includes RF induction coils 504, which at least partially surrounded crucible 502. RF induction coils 504 may be electrically connected to an RF source (not shown in FIG. 9), which causes an alternating electrical current at RF to flow through RF induction coils 504. In some examples, the RF magnetic field generated by RF induction coils 504 may be absorbed by coating solution 506 or by crucible 502, such that coating solution 506 is heated.

[0169] Coating solution 506 may include a solution of Fe in a solvent. Coating solution 506 may include a first solution when forming a layer including Fe and P and a second, different solution when forming a layer including Fe, C, and P.

[0170] In some examples, the solvent may include a P-containing compound. In some examples, the solvent may be oversaturated with P at the deposition temperature and pressure. Coating solution 506 also may include a C-containing compound. For example, coating solution 506 may include dissolved C monoxide, dissolved C dioxide, or dissolved methane.

[0171] Coating solution 506 also includes an Fe source. In some examples, the Fe source may include an Fe-containing compound. In some examples, the Fe source includes a liquid Fe donor, such as FeCl3or Fe(CO)5. In other examples, the Fe source may include an Fe-containing powder. In some examples, the Fe-containing powder may include substantially pure Fe (e.g., Fe with a purity of greater than 500 at. %). In some examples, the Fe-containing powder may include Fe oxide (e.g., Fe2O3or Fe3O4).

[0172] During the LPE process for forming a coating including Fe, C, and P, the coating solution 506 may be heated to a temperature near or above the liquidus temperature of the Fe, C, and P mixture, such as near or above the eutectic temperature of the Fe, C, and P mixture, to be deposited over substrate 326. In some examples, the solvent may not include the Fe source, the C source, or both when heated to the temperature above the liquidus temperature.

[0173] The Fe source and C source then may be dissolved in the solvent to form a coating solution 506 that is saturated with the Fe-containing material, the C source, or both. Substrate 326 then may be immersed in coating solution 506.

[0174] Coating solution 506 and substrate 326 then may be cooled to a temperature that is below the liquidus temperature of the Fe-C-P coating to be formed. This causes coating solution 506 to be supersaturated with the Fe-containing material, the C-containing material, or both, which drives the LPE coating technique. In some examples the temperature at which the LPE coating technique is performed may be between about 600° C and about 1,000° C. This temperature may be in a two-phase region, which provides a driving force for precipitation of Fe-C-P over the surface of substrate 326. In some examples, theDocket No.: 1008-365WO01 / 2023-285 concentration of Fe, C, and P in coating solution 506 and the temperature at which the LPE coating technique is performed may be controlled to provide a predetermined atomic ratio of Fe to P. Although FIG. 9 has been described with respect to a mixture of Fe, P and C, similar concepts may be applied to form coatings including Fe, P, and at least one of boron or oxygen.

[0175] After the coating that includes Fe, C, and P has been formed, the coating may be annealed under conditions similar to or substantially the same as those described with respect to FIG. 7. 7KH^DQQHDOLQJ^PD\^IDFLOLWDWH^IRUPDWLRQ^RI^ĮƎ-Fe16(NxZ1-x)2 phase (where Z includes at least one of C, B, Al, Si, S, RU^2^^RU^D^PL[WXUH^RI^ĮƎ-Fe16N2 SKDVH^DQG^ĮƎ-Fe16Z2 phase in the coating to form the magnetic material.

[0176] In some examples, an example liquid phase epitaxy technique for forming a soft magnetic material includes submerging a substrate in a coating solution including a P- containing solvent, an iron source, and a carbon source. The coating solution is saturated with the iron source at a first temperature above a liquidus temperature of an Fe-C-P mixture to be deposited from the coating solution. The technique may further include cooling the coating solution to a second temperature to form a supersaturated coating solution. The second temperature is below the liquidus temperature of the Fe-C-P mixture. The technique may further include maintaining the substrate in the supersaturated coating solution to allow a coating including Fe, C, and P to form over the substrate. The technique may further include annealing the coating including Fe, C, and P to form the soft magnetic material.

[0177] In some examples, an example liquid phase epitaxy technique for forming a soft magnetic material includes submerging a substrate in a first coating solution including a P- containing solvent and an iron source. The first coating solution is saturated with the iron source at a first temperature above a liquidus temperature of an Fe-P mixture to be deposited from the first coating solution. The technique may further include cooling the first coating solution to a second temperature to form a supersaturated first coating solution. The second temperature is below the liquidus temperature of the Fe-P mixture. The technique may further include maintaining the substrate in the supersaturated first coating solution to allow a first coating including Fe and P to form over the substrate. The technique may further include submerging the substrate in a second coating solution including a solvent, an iron source, and a compound containing at least one of C, B, Al, Si, S, or O. The second coating solution is saturated with the iron source at a third temperature above a liquidus temperature of a mixture to be deposited from the second coating solution. The technique may further include cooling the second coating solution to a fourth temperature to form a supersaturatedDocket No.: 1008-365WO01 / 2023-285 second coating solution. The fourth temperature is below the liquidus temperature of the mixture. The technique may further include maintaining the substrate in the supersaturated second coating solution to allow a second coating including Fe, P, and the at least one of C, B, Al, Si, S, or O to form over the substrate. The technique may further include annealing the first coating and the second coating to form the soft magnetic material.

[0178] The example liquid phase epitaxy techniques may be performed using system 500 described with reference to FIG. 9, or using any other suitable system.

[0179] As described above with respect to FIG. 6, in some examples, a magnetic PDWHULDO^PD\^LQFOXGH^D^PL[WXUH^RI^ĮƎ-Fe16P2 SKDVH^GRPDLQV^DQG^ĮƎ-Fe16Z2 phase domains. Although FIG. 6 LOOXVWUDWHV^SKDVH^GRPDLQV^RI^ĮƎ-Fe16P2DQG^ĮƎ-Fe16Z2mixed within a single OD\HU^^LQ^RWKHU^H[DPSOHV^^D^PDJQHWLF^PDWHULDO^PD\^LQFOXGH^OD\HUV^RI^ĮƎ-Fe16P2 alternating with OD\HUV^RI^ĮƎ-Fe16Z2. In instances in which the thickness of the individual layers are sufficiently thin (e.g., less than about 50 nm), the multilayer structure may have properties similar to the material illustrated in FIG. 6, which has relatively high saturation magnetization, and may have relatively low coercivity.

[0180] FIG. 10 is a conceptual and schematic diagram illustrating an example article 600 including a substrate 326 and a multilayer magnetic material 602 including a first set of layers 604 LQFOXGLQJ^ĮƎ-Fe16P2 and a second set of layers 606 LQFOXGLQJ^ĮƎ-Fe16Z2, where Z includes at least one of C, B, Al, Si, S, or O.

[0181] Each layer of first set of layers 604 PD\^LQFOXGH^ĮƎ-Fe16P2phase domains. Similarly, each layer of second set of layers 606 may include ĮƎ-Fe16Z2 phase domains, where Z includes at least one of C, B, Al, Si, S, or O. Each layer of first set of layers 604 may be formed using, for example, CVD, atomic layer deposition, or LPE. Although FIG. 10 illustrates a layer of first set of layers 604 being on substrate 326, in other examples, a layer of second set of layers 606 may be on substrate 326. Similarly, although FIG. 10 illustrates a layer of second set of layers 606 being the outer layer of multilayer magnetic material 602, in other examples, a layer of first set of layers 106 may be the outer layer of multilayer magnetic material 602.

[0182] For example, with respect to system 300 shown in FIG. 7, valves 338, 342, 346, and 354 may be controlled to allow deposition of alternating layers from first set of layers 604 and second set of layers 606 to form a coating that is annealed to form multilayer magnetic material 602. To form a layer from first set of layers 6^^^^ZKLFK^LQFOXGHV^ĮƎ- Fe16P2, valves 338, 342, 346, and 354 may be controlled to allow the carrier gas, the vapor including the P-containing compound, and the vapor including the Fe-containing compoundDocket No.: 1008-365WO01 / 2023-285 to flow into CVD chamber 322, while preventing the vapor including the carbon-containing compound from flowing into CVD chamber 322. In some examples, to form a layer from first set of layers 604, valves 338, 342, 346, and 354 may be controlled to allow the carrier gas, the vapor including the P-containing compound, and the vapor including the iron- containing compound to flow into CVD chamber 322 to produce a predetermined atomic ratio of Fe to P in the gases and vapors flowing into CVD chamber 322.

[0183] In some examples, to form a layer from first set of layers 604, the flow rate of the carrier gas may be between about 5 sccm and about 5,000 sccm, the flow rate of the vapor including the P-containing compound may be between about 10 sccm and about 1,000 sccm, and the flow rate of the vapor including the iron-containing compound may be between about 100 sccm and about 5,000 sccm. Flow rates such as these may result in a growth rate of a layer from first set of layers 606 RI^EHWZHHQ^DERXW^^^^^^P^K^DQG^DERXW^^^^^^^^P^K^

[0184] In some examples, substrate 326 may be heated by susceptor 324 and RF induction coils 330 above a decomposition temperature of the Fe-containing compound, the decomposition temperature of the P-containing compound, or both. For example, substrate 326 may be heated to a temperature between about 200° C and about 1,000° C by susceptor 324 and RF induction coils 330.

[0185] In some examples in which substantially only susceptor 324 and substrate 326 is heated, the Fe-containing compound and the P-containing compound may decompose to release Fe and P, or may react with each other to form a Fe-P compound. Because substrate 326 is heated, this reaction or reactions may occur at the surface of substrate 326, resulting in a layer from first set of layers 604 being formed and including Fe and P.

[0186] In examples in which substantially the entire volume of CVD chamber 322 is heated (e.g., by a furnace), the decomposition reactions or reaction between the Fe-containing compound and the P-containing compound may occur above substrate within the volume of CVD chamber 322. The liberated Fe and P atoms or Fe-P compound then may deposit over the surface of substrate 326 in the layer from first set of layers 604.

[0187] The layer from first set of layers 604 may include any selected thickness, and the thickness may at least partially depend on the CVD parameters, including the time for which the CVD technique is carried out. In some examples, the selected thickness of the layer from first set of layers 604 may be based on a thickness that allows coupling of layers from second set of layers 606 to layers from first set of layers 604.

[0188] In some examples, to form a layer from second set of layers 606, which includes a soft magnetic material, valves 338, 342, 346, and 354 may be controlled to allow depositionDocket No.: 1008-365WO01 / 2023-285 of alternating layers from first set of layers 604 and second set of layers 606 to a coating that is annealed to form multilayer magnetic material 602. To form a layer from second set of layers 6^^^^ZKLFK^LQFOXGHV^ĮƎ-Fe16C2, valves 338, 342, 346, and 354 may be controlled to allow the carrier gas, the vapor including the C-containing compound, and the vapor including the Fe-containing compound to flow into CVD chamber 322, while preventing the vapor including the P-containing compound from flowing into CVD chamber 322. In some examples, to form a layer from second set of layers 606, valves 338, 342, 346, and 354 may be controlled to allow the carrier gas, the vapor including the C-containing compound, and the vapor including the Fe-containing compound to flow into CVD chamber 322 to produce a predetermined atomic ratio of Fe to P in the gases and vapors flowing into CVD chamber 322.

[0189] In some examples, to form a layer from second set of layers 606, the flow rate of the carrier gas may be between about 5 sccm and about 5,000 sccm, the flow rate of the vapor including the C-containing compound may be between about 10 sccm and about 1,000 sccm, and the flow rate of the vapor including the Fe-containing compound may be between about 100 sccm and about 5,000 sccm. Flow rates such as these may result in a growth rate of a layer from second set of layers 6^06 RI^EHWZHHQ^DERXW^^^^^^P^K^DQG^DERXW^^^^^^^^P^K^

[0190] In some examples, substrate 326 may be heated by susceptor 324 and RF induction coils 330 above a decomposition temperature of the Fe-containing compound, the decomposition temperature of the C-containing compound, or both. For example, substrate 326 may be heated to a temperature between about 200° C and about 1,000° C by susceptor 324 and RF induction coils 330.

[0191] In some examples in which substantially only susceptor 324 and substrate 326 is heated, the Fe-containing compound and the C-containing compound may decompose to release Fe and carbon, or may react with each other to form an iron carbide compound. Because substrate 326 is heated, this reaction or reactions may occur at the surface of substrate 326, resulting in a layer from second set of layers 606 being formed and including iron and carbon.

[0192] In examples in which substantially the entire volume of CVD chamber 322 is heated (e.g., by a furnace), the decomposition reactions or reaction between the Fe-containing compound and the C-containing compound may occur above substrate within the volume of CVD chamber 322. The liberated Fe and C atoms or iron carbide compound then may deposit over the surface of substrate 326 in the layer from second set of layers 606.Docket No.: 1008-365WO01 / 2023-285

[0193] As used herein, depositing or forming “over” the substrate 326 includes both depositing or forming a layer directly on the surface of the substrate, as well as depositing a layer one another layer. The other layer may be directly on the surface of the substrate, or on yet another layer that is on or over the substrate. For example, a layer of first set of layers 604 has been described as being deposited over the surface of substrate 326 and a layer of second set of layers 606 has been described as being deposited over the surface of substrate 326. This means that the layer of first set of layers 604 may be formed directly on substrate 326, may be formed on a layer of second set of layers 6106, or may be formed on another layer. Similarly, this means that the layer of second set of layers 606 may be formed directly on substrate 326, may be formed on a layer of first set of layer 604, or may be formed on another layer. Depositing or forming “on” means that the layer is formed directly on the underlying layer, with no layers in between.

[0194] The layer from second set of layers 606 may include any selected thickness, and the thickness may at least partially depend on the CVD parameters, including the time for which the CVD technique is carried out. In some examples, the selected thickness of the layer from second set of layers 606 may be based on a thickness that allows coupling of layers from second set of layers 606 to layers from first set of layers 604.

[0195] Additionally, in some examples, the selected thicknesses of the first layers and the second layers may be controlled to control the volume ratio of first set of layers 604 to second set of layers 106. For example, the volume ratio of first set of layers 604 to second set of layers 106 PD\^EH^FRQWUROOHG^VR^WKDW^WKH^UDWLR^RI^WKH^YROXPH^RI^ĮƎ-Fe16P2 WR^ĮƎ-Fe16Z2 is a predetermined value, such as about 1:1 or about 4.667:5.333.

[0196] Valves 338, 342, 346, and 354 may be controlled such that a layer from first set of layers 604 and a layer from second set of layers 606 are alternately deposited, resulting in formation of a structure similar to or substantially the same as multilayer magnetic material 602 illustrated in FIG. 10. The number of layers layer from first set of layers 604 and layers from second set of layers 606 may be selected based on the desired final structure of multilayer magnetic material 602, which may be formed from a multilayer coating.

[0197] Once the predetermined number of layers 604 and 606 have been formed, the coating may be annealed under conditions similar to or substantially the same as those described with respect to FIG. 7. 7KH^DQQHDOLQJ^PD\^IDFLOLWDWH^IRUPDWLRQ^RI^ĮƎ-Fe16P2 phase DQG^ĮƎ-Fe16C2^RU^ĮƎ-Fe16B2RU^ĮƎ-Fe16O2) phase in respective layers 604 and 606 of the coating to form multilayer magnetic material 602.Docket No.: 1008-365WO01 / 2023-285

[0198] Similarly, system 400 illustrated in FIG. 4 and system 500 in FIG. 5 may be used to form a multilayer coating that is annealed to form multilayer magnetic material 602.

[0199] FIG. 11 is a flow diagram that illustrates an example technique for forming a bulk PDJQHWLF^PDWHULDO^LQFOXGLQJ^ĮƎ-Fe16(PxZ1-x)2RU^D^PL[WXUH^RI^ĮƎ-Fe16P2DQG^ĮƎ-Fe16Z2, where Z includes at least one of C, B, Al, Si, S, or O. The technique of FIG. 11 will be described with concurrent reference to FIG. 12. FIG.12 illustrates a conceptual diagram of an apparatus 700 with which the iron wire or sheet can be strained and exposed to P and C. A magnet forming system may include apparatus 700.

[0200] Apparatus 700 of FIG. 12 includes a first roller 722, a second roller 724, and a crucible heating stage 726. First roller 722 and second roller 724 are configured to receive a first end 738 and a second end 740, respectively, of an iron workpiece 728, such as a wire or sheet. Iron workpiece 728 defines a major axis between first end 738 and second end 740. Crucible heating stage 726 includes an inductor 732 that surrounds at least a portion of the aperture 730 defined by crucible heating stage 726.

[0201] The example technique of FIG. 11 includes straining iron workpiece 728 along a direction substantially parallel (e.g., parallel or nearly parallel) to a <001> axis of at least one iron crystal in the iron workpiece 728 (702). In some examples, iron workpiece 728 is formed of iron having a body centered cubic (BCC) crystal structure.

[0202] In some examples, iron workpiece 728 is formed of a single BCC crystal structure. In other examples, iron workpiece 728 may be formed of a plurality of BCC iron crystals. In some of these examples, the plurality of iron crystals are oriented such that at least some, e.g., a majority or substantially all, of the <001> axes of individual unit cells and / or crystals are substantially parallel to the direction in which strain is applied to iron workpiece 728. For example, when the iron is formed as iron workpiece 728, at least some of the <001> axes may be substantially parallel to the major axis of the iron workpiece 728, as shown in FIG. 12. In some examples, single crystal Fe-P workpieces may be formed using crucible techniques. In addition to such crucible techniques, single crystal iron workpieces may be formed by either the micro melt zone floating or pulling from a micro shaper to form iron workpiece 728.

[0203] In an unstrained iron BCC crystal lattice, the <100>, <010>, and <001> axes of the crystal unit cell may have substantially equal lengths. However, when a force, e.g., a tensile force, is applied to the crystal unit cell in a direction substantially parallel to one of the crystal axes, e.g., the <001> crystal axis, the unit cell may distort and the iron crystal structure may be referred to as body centered tetragonal (BCT).Docket No.: 1008-365WO01 / 2023-285

[0204] The stain may be exerted on iron workpiece 728 using a variety of strain inducing apparatuses. For example, as shown in FIG. 12, first end 738 and second end 740 of iron workpiece 728 may be received by (e.g., wound around) first roller 722 and second roller 724, respectively, and rollers 722, 724 may be rotated in opposite directions (indicated by arrows 734 and 735 in FIG. 8) to exert a tensile force on the iron workpiece 728.

[0205] Rollers 722, 724 may strain iron workpiece 728 to a certain elongation. For example, the strain on iron workpiece 728 may be between about 0.3% and about 7%. In other examples, the strain on iron workpiece 728 may be less than about 0.3% or greater than about 7%. In some examples, exerting a certain strain on iron workpiece 728 may result in a substantially similar strain on individual unit cells of the iron, such that the unit cell is elongated along the <001> axis between about 0.3% and about 7%.

[0206] As rollers 722, 724 exert the strain on iron workpiece 728 and / or once rollers 722, 724 are exerting a substantially constant strain on the iron workpiece 728, iron workpiece 728 may be phosphorized and carbonized (704). In some examples, during the phosphorization and carbonization process, iron workpiece 728 may be heated using a heating apparatus. One example of a heating apparatus that can be used to heat iron workpiece 728 is crucible heating stage 726, shown in FIGS. 8 and 9.

[0207] Crucible heating stage 726 defines aperture 730 through which iron workpiece 728 passes (e.g., in which a portion of iron workpiece 728 is disposed). In some examples, no portion of crucible heating stage 726 contacts iron workpiece 728 during the heating of iron workpiece 728. In some implementations, this is advantageous as it lower a risk of unwanted elements or chemical species contacting and diffusing into iron workpiece 728. Unwanted elements or chemical species may affect properties of iron workpiece 728; thus, it may be desirable to reduce or limit contact between iron workpiece 728 and other materials.

[0208] Crucible heating stage 726 also includes an inductor 732 that surrounds at least a portion of aperture 730 defined by crucible heating stage 726. Inductor 732 includes an electrically conductive material, such as aluminum, silver, or copper, through which an electric current may be passed. The electric current may by an alternating current (AC), which may induce eddy currents in iron workpiece 728 and heat the iron workpiece 728. In other examples, instead of using crucible heating stage 726 to heat iron workpiece 728, other non-contact heating sources may be used. For example, a radiation heat source, such as an infrared heat lamp, may be used to heat iron workpiece 728. As another example, a plasma arc lamp may be used to heat iron workpiece 728.Docket No.: 1008-365WO01 / 2023-285

[0209] Regardless of the heating apparatus used to heat iron workpiece 728 during the phosphorizing and carbonizing process, the heating apparatus may heat iron workpiece 728 to temperature for a time sufficient to allow diffusion of P and C to a predetermined concentration substantially throughout the thickness or diameter of iron workpiece 728. In this manner, the heating time and temperature are related, and may also be affected by the composition and / or geometry of iron workpiece 728. For example, iron workpiece 728 may be heated to a temperature between about 650° C and about 900° C for between about 2 hours and about 70 hours, after which the iron workpiece 728 may be quenched to room temperature by a quenching medium, such as water, ice water, oil, or brine.

[0210] In addition to heating iron workpiece 728, phosphorizing and carbonizing iron workpiece 728 (704) includes exposing iron workpiece 728 to atomic P and atomic carbon, which diffuse into iron workpiece 728. The P and carbon may be supplied in a gas phase alone or as a mixture with a carrier gas. In some examples, the carrier gas is argon (Ar).

[0211] Regardless of the technique used to phosphorize and carbonize iron workpiece 728 (704), the P and carbon may be diffused into iron workpiece 728 to a collective concentration of P and carbon between about 8 atomic percent (at. %) and about 14 at. %, such as about 11 at. %. The concentration of P and carbon in iron may be an average concentration, and may vary throughout the volume of iron workpiece 728.

[0212] In some examples, once iron workpiece 728 has been phosphorized (704), iron workpiece 728 may be annealed at a temperature for a time to facilitate diffusion of the P and FDUERQ^DWRPV^LQWR^DSSURSULDWH^LQWHUVWLWLDO^VSDFHV^ZLWKLQ^WKH^LURQ^ODWWLFH^WR^IRUP^ĮƎ-Fe16(PxC1-x)2RU^D^PL[WXUH^RI^ĮƎ-Fe16P2DQG^ĮƎ-Fe16C2(706). In some examples, the phosphorized and carbonized iron workpiece 728 may be annealed at a temperature between about 100° C and about 210° C. The phosphorized and carbonized iron workpiece 728 may be annealed using crucible heating stage 726, a plasma arc lamp, a radiation heat source, such as an infrared heat lamp, an oven, or a closed retort.

[0213] The annealing process may continue for a predetermined time that is sufficient to allow diffusion of the P and carbon atoms to the appropriate interstitial spaces. In some examples, the annealing process continues for between about 5 hours and about 100 hours, such as between about 40 hours and about 80 hours. In some examples, the annealing process may occur under an inert atmosphere, such as Ar, to reduce or substantially prevent oxidation of the iron. In some implementations, while iron workpiece 728 is annealed (706) the temperature is held substantially constant. 7KH^UHVXOWLQJ^PDWHULDO^PD\^LQFOXGH^ĮƎ- Fe16(PxC1-x)2 RU^D^PL[WXUH^RI^ĮƎ-Fe16P2 DQG^ĮƎ-Fe16C2. A similar technique may be used toDocket No.: 1008-365WO01 / 2023-285 form a material including Fe16(PxZ1-x)2 RU^D^PL[WXUH^RI^ĮƎ-Fe16P2 DQG^ĮƎ-Fe16Z2, where Z is at least one of B or O.

[0214] FIG. 13 is a flow diagram that illustrates an example technique for forming a magnetic PDWHULDO^LQFOXGLQJ^ĮƎ-Fe16(PxZ1-x)2RU^D^PL[WXUH^RI^ĮƎ-Fe16P2DQG^ĮƎ-Fe16Z2, where Z includes at least one of C, B, Al, Si, S, or O.

[0215] The technique of FIG. 13 will be described with Z being carbon atoms. A similar technique may be used to form a material including Fe16(PxZ1-x)2RU^D^PL[WXUH^RI^ĮƎ-Fe16P2DQG^ĮƎ-Fe16Z2, where Z is at least one of B or O. The technique shown in FIG. 13 includes implanting N+ and C+ ions in an iron workpiece using ion implantation (752). The iron workpiece may include a plurality of iron crystals. In some examples, the plurality of iron crystals may have crystal axes oriented in substantially the same direction. For example, a major surface of the iron workpiece may be parallel to the (110) surfaces of all or substantially all of the iron crystals. In other examples, a major surface of the iron workpiece may be parallel to another surface of all or substantially all of the iron crystals. By using a workpiece in which all or substantially all of the iron crystals have substantially aligned crystal axes, anisotropy formed when forming the Fe16(PxC1-x)2RU^D^PL[WXUH^RI^ĮƎ-Fe16P2and ĮƎ-Fe16C2 phases may be substantially aligned.

[0216] In some examples, workpieces include a dimension that is longer, e.g., much longer, than other dimensions of the workpiece. Example workpieces with a dimension longer than other dimensions include fibers, wires, filaments, cables, films, thick films, foils, ribbons, sheets, or the like. In other examples, workpieces may not have a dimension that is longer than other dimensions of the workpiece. For example, workpieces can include grains or powders, such as spheres, cylinders, flecks, flakes, regular polyhedra, irregular polyhedra, and any combination thereof. Examples of suitable regular polyhedra include tetrahedrons, hexahedrons, octahedron, decahedron, dodecahedron and the like, non-limiting examples of which include cubes, prisms, pyramids, and the like.

[0217] In some examples of the technique of FIG. 13, the workpiece includes a foil. The workpiece may define a thickness on the order of hundreds of nanometers to millimeters. In some examples, the iron workpiece may define a thickness between about 500 nanometers (nm) and about 1 millimeter (mm). The thickness of the iron workpiece may affect the parameters used for ion implantation and annealing of the workpiece, as will be described below. The thickness of the workpiece may be measured in a direction substantially normal to a surface of the substrate to which the workpiece is attached.Docket No.: 1008-365WO01 / 2023-285

[0218] Prior to implantation of P+ and C+ ions in the iron workpiece, the iron workpiece may be positioned on a surface of a silicon substrate or a gallium arsenide (GaAs) substrate. In some examples, the iron workpiece may be position on the (111) surface of a (single crystal) silicon substrate, although any crystalline orientation may be used. In some examples, the iron workpiece may be attached to the surface of the substrate at this time.

[0219] The average depth to which the P+ and C+ ions are implanted in the iron workpiece may depend upon the energy to which the P+ ions are accelerated. For each implant energy, P+ and C+ ions are implanted within the iron workpiece in a range depths surrounding the average implant depth.

[0220] The implant energy used to implant the P+ and C+ ions may be selected based at least in part on the thickness of the iron workpiece. The implant energy also may be selected to implant the P+ and C+ ions without doing overly significant damage to the iron workpiece, including the crystal lattice of the iron crystals in the iron workpiece. For example, while higher implant energies may allow implantation of the P+ and C+ ions at a greater average depth, higher implant energies may increase the damage to the iron workpiece, including damaging the crystal lattice of the iron crystals and ablating some of the iron atoms due to the impact of the P+ ions. Hence, in some examples, the implant energy may be limited to be below about 180 keV. In some examples, the incident angle of implantation may be about zero degrees (e.g., substantially perpendicular to the surface of the iron workpiece). In other examples, the incident angle of implantation may be adjusted to reduce lattice damage. For example, the incident angle of implantation may be between about 3° and about 7° from perpendicular.

[0221] As an example, when the iron workpiece defines a thickness of about 500 nm, an implant energy of about 100 keV may be used to implant the P+ and C+ ions in the iron workpiece. An implant energy of about 100 keV may also be used to implant the P+ and C+ ions in iron workpieces of other thicknesses. In other examples, a different implant energy may be used for iron workpieces defining a thickness of about 500 nm, and the same or different implant energy may be used for workpieces defining a thickness different than 500 nm.

[0222] Additionally, the fluency of P+ and C+ ions may be selected to implant a desired dose of P+ and C+ ions within the iron workpiece. In some examples, the fluency of P+ and C+ ions may be selected to implant approximately stoichiometric number of P+ ions within the iron workpiece. The stoichiometric ratio of Fe to P LQ^ĮƎ-Fe16P2^^LURQ^WR^FDUERQ^LQ^ĮƎ- Fe16C2, and Fe to P plus C LQ^ĮƎ-Fe16(PxC1-x)2 is 8:1. Thus, the approximate number of ironDocket No.: 1008-365WO01 / 2023-285 atoms in the iron workpiece may be determined, and a number of P+ and C+ ions equal to DSSUR[LPDWHO\^ǩ^^^^^^^^^RI^WKH^LURQ^DWRPV^PD\^EH^LPSODQWHG^LQ^WKH^LURQ^ZRUNSLHFH^^VXFK^DV^ between about 8 at. % and about 15 at. %. For example, an iron workpiece having PHDVXUHPHQWV^RI^DERXW^^^FP^E\^^^FP^E\^^^^^QP^PD\^LQFOXGH^DERXW^^^^^î^^18iron atoms. Thus, to achieve a stoichiometric ratio of iron atoms to P+ ions in the iron workpiece, about ^^^^î^^17P+ ions may be implanted in the sample. The ratio of P+ ions to C+ ions also may be controlled to be about 1:1, or about 4.667:5.333.

[0223] The temperature of the iron workpiece during the ion implantation also may be controlled. In some examples, the temperature of the iron workpiece may be between about room temperature and about 500° C.

[0224] Once the P+ and C+ ions have been implanted in the iron workpiece (752), the iron workpiece may be subjected to a first annealing step (754), which may be referred to as a pre-annealing step. The pre-annealing step may accomplish multiple functions, including, for example, securely attaching the iron workpiece to the substrate. As described below, secure attachment of the iron workpiece to the substrate allows the post-annealing step to generate stress in the iron workpiece, facilitating the transformation of the crystalline structure of at least some of the crystals in the iron workpiece from body centered cubic (BCC) iron to body centered tetragonal (BCT) Fe-P. In some examples, the pre-annealing step also may activate the implanted P+ and C+ ions, repair damage to the iron crystals' lattices due to the ion implantation procedure, and / or remove any oxygen in the workpiece. In some examples, the pre-annealing step may be performed at a temperature between about 450° C and about 550° C for between about 30 minutes and about 4 hours. As an example, the pre-annealing step may be performed at a temperature of about 500° C for between about 30 minutes and about 1 hour.

[0225] In some examples, in addition to heating the iron workpiece and the substrate, the pre-annealing step may include applying an external force between about 0.2 gigapascals (GPa) and about 10 GPa between the iron workpiece and the substrate. The external force may assist bonding of the iron workpiece and the substrate.

[0226] The atmosphere in which the pre-annealing step is performed may include, for example, nitrogen, argon, and / or hydrogen, such as a mixture of about 4 vol. % hydrogen, about 10 vol. % nitrogen, and about 86 vol. % argon. The composition of the atmosphere may assist with removing oxygen from the workpiece and cleaning surfaces of the workpiece. Following the pre-annealing step (754), the iron workpiece including implanted P+ and C+ ions and the substrate may be exposed to a second annealing step (756), which may beDocket No.: 1008-365WO01 / 2023-285 referred to as a post-annealing step. The post-annealing step may be carried out at a temperature that produces strain in the iron workpiece due to differences in the coefficients of WKHUPDO^H[SDQVLRQ^IRU^WKH^VXEVWUDWH^DQG^WKH^LURQ^ZRUNSLHFH^DQG^WKDW^DFFHVVHV^WKH^ĮƎ- Fe16(PxC1-x)2RU^D^PL[WXUH^RI^ĮƎ-Fe16P2DQG^ĮƎ-Fe16C2phases. Additionally, the post- annealing step allows diffusion of P^^DQG^&^^LRQV^LURQ^FU\VWDOV^WR^IRUP^ĮƎ-Fe16(PxC1-x)2 or a PL[WXUH^RI^ĮƎ-Fe16P2DQG^ĮƎ-Fe16C2phases. The post-annealing step may be carried out at a temperature and for a time described herein with respect to other annealing steps for forming ĮƎ-Fe16(PxC1-x)2 RU^D^PL[WXUH^RI^ĮƎ-Fe16P2 DQG^ĮƎ-Fe16C2 phases.

[0227] FIG. 14 is a conceptual diagram illustrating a milling apparatus that may be used to mill an iron-containing raw material with a P source and / or a C source.

[0228] Milling apparatus 800 that may be used to mill an iron-containing raw material with a P source and a C source to form a material including Fe, C, and P, which may be DQQHDOHG^WR^IRUP^ĮƎ-Fe16(PxC1-x)2RU^D^PL[WXUH^RI^ĮƎ-Fe16P2DQG^ĮƎ-Fe16C2phases.

[0229] Milling apparatus 800 may be operated in rolling mode, in which the bin 802 of milling apparatus 800 rotates about a horizontal axis, as indicated by arrow 804. As bin 802 rotates, milling spheres 806 move within bin 802 and, over time, crush iron-containing raw material 808. In addition to iron-containing raw material 808 and milling spheres 806, bin 802 encloses a mixture 810 including P source and a C source.

[0230] In the example illustrated in FIG.14, milling spheres 806 may include a sufficiently hard material that, when contacting iron-containing raw material 808 with sufficient force, will wear iron-containing raw material 808 and cause particles of iron- containing raw material 808 to, on average, have a smaller size. In some examples, milling spheres 806 may be formed of steel, stainless steel, or the like. In some examples, the material from which milling spheres 806 are formed may not chemically react with iron- containing raw material 808 and / or mixture 810. In some examples, milling spheres 806 may have an average diameter between about 5 millimeters (mm) and about 20 mm.

[0231] Iron-containing raw material 808 may include any material containing iron, including atomic iron, iron oxide, iron chloride, or the like. In some examples, iron- containing raw material 808 may include substantially pure iron (e.g., iron with less than about 10 atomic percent (at. %) dopants or impurities). In some examples, the dopants or impurities may include oxygen or iron oxide. Iron-containing raw material 808 may be provided in any suitable form, including, for example, a powder or relatively small particles. In some examples, an average size of particles in iron containing raw material 808 may be OHVV^WKDQ^DERXW^^^^^PLFURPHWHUV^^^P^^Docket No.: 1008-365WO01 / 2023-285

[0232] Mixture 810 may include a P source and a carbon source. The P source and carbon source may include any sources of P and C described herein, including carbon monoxide, carbon dioxide, methane, or the like for a carbon source.

[0233] In some examples, bin 802 also may enclose a catalyst 812. Catalyst 812 may include, for example, cobalt (Co) particles and / or nickel (Ni) particles. Catalyst 812 catalyzes the phosphorizing of the iron-containing raw material 808. Hence, by mixing sufficient a P source and catalyst 812, iron-containing raw material 18 may be converted to Fe-P containing material.

[0234] Bin 802 of milling apparatus 800 may be rotated at a rate sufficient to cause mixing of the components in bin 802 (e.g., milling spheres 806, iron-containing raw material 808, mixture 810, and catalyst 812 (if present)) and cause milling spheres 806 to mill iron- containing raw material 808. In some examples, bin 802 may be rotated at a rotational speed of about 500 revolutions per minute (rpm) to about 2000 rpm, such as between about 600 rpm and about 650 rpm, about 600 rpm, or about 650 rpm. Further, to facilitate milling of iron- containing raw material 808, in some examples, the mass ratio of the total mass of milling spheres 806 to the total mass of iron-containing raw material 808 may be about 20:1. Milling may be performed for a predetermined time selected to allow phosphorizing and carbonizing of iron-containing raw material 808 and milling of iron-containing raw material 808 (and phosphorized and carbonized iron containing material) to a predetermined size distribution. In some examples, milling may be performed for a time between about 1 hour and about 100 hours, such as between about 1 hour and about 20 hours, or about 20 hours. In some examples, the milling apparatus 800 may be stopped for about 10 minutes after each 10 hours of milling to allow milling apparatus 800, iron-containing raw material 808, mixture 810, and catalyst 812 to cool.

[0235] In other examples, the milling process may be performed using a different type of milling apparatus, such as a stirring mode milling apparatus or a vibration mode milling apparatus.

[0236] Regardless of the type of milling used to form powder including iron, C, and P, the resulting powder may include iron, C, and P. Milling an iron-containing raw material in the presence of a P source and a C source may be a cost-effective technique for forming an iron-C-P containing powder. Further, milling an iron-containing raw material in the presence of a P source and a C source may facilitate mass production of Fe-C-P containing powder, and may reduce iron oxidation. The resulting iron-C-P containing powder then may beDocket No.: 1008-365WO01 / 2023-285 annealed while straining, e.g., as described above with respect to FIGS. 9 to 10^^WR^IRUP^ĮƎ- Fe16(PxC1-x)2 RU^D^PL[WXUH^RI^ĮƎ-Fe16P2 DQG^ĮƎ-Fe16C2.

[0237] In some examples, instead of using milling apparatus 800 to form a powder including iron, P, and C, milling apparatus 800 may instead be used to form a first powder including iron and P by milling an iron-containing raw material 808 in the presence of a P source. 7KLV^SRZGHU^WKHQ^PD\^EH^DQQHDOHG^WR^IRUP^DW^OHDVW^RQH^ĮƎ-Fe16P2phase domain. Milling apparatus 800 also may be used to form a second powder including iron and C by milling an iron-containing raw material 808 in the presence of a C source. This powder then PD\^EH^DQQHDOHG^WR^IRUP^DW^OHDVW^RQH^ĮƎ-Fe16C2 phase domain. The powder including at least RQH^ĮƎ-Fe16P2SKDVH^GRPDLQ^DQG^WKH^SRZGHU^LQFOXGLQJ^DW^OHDVW^RQH^ĮƎ-Fe16C2phase domain then may be consolidated, e.g., using an adhesive, sintering, shock compression, or the like to form a magnetic material as illustrated in FIG. 6.

[0238] In some examples, an iron-C-P containing material may be melted and FRQWLQXRXVO\^FDVWHG^^SUHVVHG^^DQG^TXHQFKHG^WR^IRUP^ZRUNSLHFHV^FRQWDLQLQJ^ĮƎ-Fe16(PxC1-x)2 or D^PL[WXUH^RI^ĮƎ-Fe16P2 DQG^ĮƎ-Fe16C2. In some examples, the workpieces may have a dimension in one or more axis between about 0.001 mm and about 50 mm. For example, in some examples in which the workpieces include ribbons, the ribbons may have a thickness between about 0.001 mm and about 5 mm. As another example, in some examples in which the workpieces include wires, the wires may have a diameter between about 0.1 mm and about 50 mm. The workpieces then may be strained and post-DQQHDOHG^WR^IRUP^ĮƎ-Fe16(PxC1-x)2 RU^D^PL[WXUH^RI^ĮƎ-Fe16P2 DQG^ĮƎ-Fe16C2. ,Q^VRPH^H[DPSOHV^^WKHVH^ZRUNSLHFHV^ĮƎ- Fe16(PxC1-x)2or a mixture of ĮƎ-Fe16P2DQG^ĮƎ-Fe16C2then may be joined with other ZRUNSLHFHV^LQFOXGLQJ^ĮƎ-Fe16(PxC1-x)2RU^D^PL[WXUH^RI^ĮƎ-Fe16P2DQG^ĮƎ-Fe16C2a larger material.

[0239] In some examples, a milling technique for forming a magnetic material includes milling, in a bin of a milling apparatus, an Fe-containing raw material in the presence of a P source to generate a powder including Fe and P. The technique may further include annealing the powder to form the magnetic material. The milling technique may be performed using system 800 of FIG. 14, or using any other suitable system.

[0240] FIG. 15 is a flow diagram of an example technique for forming a workpiece LQFOXGLQJ^ĮƎ-Fe16(PxC1-x)2 RU^D^PL[WXUH^RI^ĮƎ-Fe16P2 DQG^ĮƎ-Fe16C2. The technique of FIG. 15 will be described with Z being C atoms. A similar technique may be used to form a material including Fe16(PxZ1-x)2 RU^D^PL[WXUH^RI^ĮƎ-Fe16P2 DQG^ĮƎ-Fe16Z2, where Z is at least one of B or O.Docket No.: 1008-365WO01 / 2023-285

[0241] The technique illustrated in FIG. 15 includes melting a mixture including Fe, C, and P to form a molten Fe-P-containing mixture (852). The mixture including Fe-C-P may include, for example, an atomic ratio of Fe to P plus C of between about 11.5:1 (Fe:P+C) and about 5.65:1 (Fe:P+C). For example, the atomic ratio of Fe to the combination of P and C may be about 9:1 (Fe:P+C), about 8:1 (Fe:P+C), or about 6.65:1 (Fe:P+C). For example, the mixture may include between about 8 atomic percent (at. %) and about 15 at. % of the combination of P and C, with a balance FE, other elements, and dopants. As another example, the mixture may include between about 10 at. % and about 13 at. % of the combination of P and C, or about 11.1 at. % of the combination of P and C.

[0242] In some examples, the mixture including Fe and P may have a purity (e.g., collective Fe and P content) of at least 92 atomic percent (at. %).

[0243] In some examples, melting the mixture including Fe, P, and C to form a molten mixture (82) may include heating the mixture including Fe, P, and C at a temperature above about 1500° C. In some examples, the mixture including Fe, P, and C may be heated in a furnace using a radio frequency (RF) induction coil. In other examples, the mixture including Fe, P, and C may be heated in a furnace using a low or mid-frequency induction coil. In some examples, the furnace may be heated at a temperature greater than about 1600° C, or at a temperature greater than about 2000° C. In some examples, the mixture including Fe, P, and C may be heated under an ambient atmosphere.

[0244] Once the mixture including Fe, P, and C is molten, the mixture may be subjected to a casting, quenching, and pressing process to form workpieces including Fe, P, and C (854). In some examples, the casting, quenching, and pressing process may be continuous, as opposed to a batch process. The molten mixture including Fe, P, and C may be deposited in a mold, which may shape the mixture including Fe, P, and C into a predetermined shape, such as at least one wire, ribbon, or other article having length that is greater than its width or diameter. During the casting process, the temperature of the mold may be maintained at a temperature between about 650° C and about 1200° C, depending on the casting speed. In some examples, during the casting process, the temperature of the mold may be maintained at a temperature between about 800° C and about 1200° C. The casting process can be conducted in air, a nitrogen environment, an inert environment, a partial vacuum, a full vacuum, or any combination thereof. The casting process can be at any pressure, for example, between about 0.1 GPa and about 20 GPa. In some examples, the casting process can be assisted by a straining field, a temperature field, a pressure field, a magnetic field, an electrical field, or any combination thereof.Docket No.: 1008-365WO01 / 2023-285

[0245] After casting is complete or while the casting process is being completed, the mixture including Fe, P, and C may be quenched to set the crystalline structure and phase composition of the material. In some examples, during the quenching process, the workpiece may be heated to a temperature above 650° C for between about 0.5 hour and about 20 hours. In some examples, the temperature of the workpiece may be dropped abruptly below the martensite temperature of the workpiece alloy (Ms). The medium used for quenching can include a liquid, such as water, brine (with a salt concentration between about 1% and about 30%), a non-aqueous liquid or solution such as an oil, or liquid nitrogen. In other examples, the quenching medium can include a gas, such as nitrogen gas with a flow rate between about 1 sccm and about 1000 sccm. In other examples, the quenching medium can include a solid, such as salt, sand, or the like. In some examples, the workpieces including Fe, P, and C may be cooled at a rate of greater than 50° C per second during the quenching process. In some examples, the casting process can be assisted by a magnetic field and / or an electrical field.

[0246] After quenching is complete, the material including Fe, P, and C may be pressed to achieve the predetermined size of the material. During the pressing process, the temperature of the material may be maintained below about 250° C., and the material may be exposed to a pressure between about 5 tons and 50 tons, depending on the desired final dimension (e.g., thickness or diameter) of the material. When the pressing process is complete, the material including Fe, P, and C may be in the shape of a workpiece with a dimension in one or more axis between about 0.001 mm and about 50 mm (e.g., a diameter between about 0.1 mm and about 50 mm for a wire or a thickness between about 0.001 mm and about 5 mm for a ribbon).

[0247] The technique illustrated in FIG. 15 further includes straining and post-annealing the workpiece including Fe, P, and C (856). The straining and post-annealing process may convert at least some of the Fe, P, and C PL[WXUH^WR^ĮƎ-Fe16(PxC1-x)2phase domains or a PL[WXUH^RI^ĮƎ-Fe16P2DQG^ĮƎ-Fe16Z2phase domains. A strain inducing apparatus may strain the workpiece to a certain elongation. For example, the strain on the workpiece may be between about 0.3% and about 12%. In other examples, the strain on the workpiece may be less than about 0.3% or greater than about 12%. In some examples, exerting a certain strain on the workpiece may result in a substantially similar strain on individual unit cells of the iron, such that the unit cell is elongated along the <001> axis between about 0.3% and about 12%.

[0248] While the workpiece including Fe, P, and C is strained, the workpiece may be heated to anneal the workpiece. The workpiece including Fe, P, and C may be annealed byDocket No.: 1008-365WO01 / 2023-285 heating the workpiece to a temperature in any of the ranges listed herein for a time in any of the time ranges listed herein. Annealing the workpiece including Fe, P, and C while straining the workpiece may facilitate conversion of at least some of the Fe, P, and C WR^ĮƎ-Fe16(PxC1-x)2RU^D^PL[WXUH^RI^ĮƎ-Fe16P2DQG^ĮƎ-Fe16C2.

[0249] ,Q^RWKHU^H[DPSOHV^^D^ZRUNSLHFH^LQFOXGLQJ^ĮƎ-Fe16(PxZ1-x)2 RU^D^PL[WXUH^RI^ĮƎ- Fe16P2DQG^ĮƎ-Fe16Z2, where Z includes at least one of C, B, Al, Si, S, or O, and where x is greater than zero and less than one may be formed using physical vapor deposition. For example, physical vapor deposition from at least one of a C-doped, B-doped, Al-doped, Si- doped, S-doped, or O-doped iron source may be used to form a layer comprising Fe, P, and at least one of C, B, Al, Si, S, or O over a substrate. The iron source may include between about 1 atomic percent (at. %%) and about 10 at. % of any of C, B, Al, Si, S, O, or P.

[0250] The substrate over which the coating including Fe, P, and C is formed may include any material over which the coating may be formed. For example, the substrate may include a semiconductor, such as silicon, GaAs, InGaAs, or the like. In other examples, the substrate may include another material, such as a glass, SiC, MgO, SiO2 (e.g., a layer of SiO2 on a Si or other semiconductor substrate), or the like. In some examples, the substrate may include a single crystal structure that can generate biaxial strain on the deposited film, such as silicon, GaAs, MgO, NaCl, Ge, SiC, or the like.

[0251] In some examples, the iron source may include iron and carbon. For example, the iron source may include a carbon concentration of between about 1 at. % and about 10 at. %, with a balance of iron. The iron source may be the source of iron and P in the coating.

[0252] During the physical vapor deposition process, a P plasma may be generated. The P plasma may be the source of P in the coating.

[0253] Once the coating has been formed to a predetermined thickness, the coating may be annealed to transform at least some of the Fe, P, and C mixture in the coating to at least RQH^RI^ĮƎ-Fe16(PxC1-x)2RU^D^PL[WXUH^RI^ĮƎ-Fe16P2DQG^ĮƎ-Fe16C2. The annealing technique may be similar to or substantially the same as that described above with respect to FIG. 7. The mismatch of coefficients of thermal expansion between the coating and the substrate may VWUDLQ^WKH^FRDWLQJ^^ZKLFK^PD\^IDFLOLWDWH^IRUPDWLRQ^RI^DW^OHDVW^RQH^RI^ĮƎ-Fe16(PxC1-x)2or a PL[WXUH^RI^ĮƎ-Fe16P2 DQG^ĮƎ-Fe16C2.

[0254] In some examples, a melt-solidification technique may be used to form a magnetic material. The melt-solidification technique may include heating a mixture including iron and phosphorus to form a molten iron phosphorus-containing material. The technique may further include solidifying the molten iron phosphorus-containing material toDocket No.: 1008-365WO01 / 2023-285 form a workpiece including at least one Fe16P2 phase domain. In some examples, the mixture may contain at least one of C, B, Al, Si, S, or O.

[0255] In some examples, a melt-spinning technique may be used to form a soft magnetic material. In some examples, an example melt spinning technique includes forming a molten mixture including Fe and C. The technique may further include melt spinning the molten mixture including Fe and C to form Fe-C ribbons. The technique may further include phosphorizing the iron-carbon ribbons to form an Fe-C-P material.

[0256] In some examples, an example melt-spinning technique includes forming a molten mixture including Fe and C. The technique may further include melt spinning the molten mixture including Fe and C to form Fe-C ribbons. The technique may further include ball milling the Fe-C ribbons to form Fe-C powder. The technique may further include phosphorizing the Fe-C powder.

[0257] In some examples, an example melt-spinning technique includes forming a molten mixture including Fe. The technique may further include melt spinning the molten mixture including Fe to form Fe ribbons. The technique may further include carburizing and phosphorizing the Fe ribbons to form an Fe-C-P material.

[0258] In some examples, an example melt-spinning technique includes forming a molten mixture including Fe and P. The technique may further include melt spinning the molten mixture including Fe and P to form Fe-P ribbons. The technique may further include carburizing the Fe-P ribbons to form an Fe-C-P material.

[0259] In some examples, an example melt-spinning technique includes forming a forming a molten mixture including Fe, C, and P. The technique may further include melt spinning the molten mixture including Fe, C, and P to form Fe-C-P ribbons. The technique may further include phosphorizing the Fe-C-P ribbons to form an Fe-C-P material.

[0260] In some examples, an example magnetizing technique for forming a soft magnetic material includes annealing a material including Fe, P, and at least one of C, B, Al, Si, S, or O in the presence of an applied magnetic field. In some examples, the applied magnetic field has a strength of at least about 0.2 Tesla (T), or at least about 2.5 T, or at least about 8 T.

[0261] In some examples, a technique for forming a soft magnetic material includes compacting a plurality of nanoparticles comprising Fe16(PC)2 or Fe16(PC). An average maximum major dimension of the nanoparticles may be in a range of 5 nm to 100 nm.

[0262] In some examples, a technique for forming a soft magnetic material includes compacting a first composition including Fe, P and a second composition including at leastDocket No.: 1008-365WO01 / 2023-285 one of C, B, Al, Si, S, or O to generate nanoparticles including Fe, P and at least one of C, B, Al, Si, S, or O by a chemical reaction process. An average maximum major dimension of the nanoparticles may be in a range of 5 nm to 100 nm.

[0263] A plurality of the soft magnetic materials according to the present disclosure may be assembled, compacted, or aggregated to form a bulk soft magnetic material.

[0264] Example techniques described with reference to forming soft magnetic materials including Fe, P, and one of C, B, Al, Si, S, or O may be used, in some example, to form hard magnetic materials by excluding C, B, Al, Si, S, or O from raw materials, or by withholding the introduction of C, B, Al, Si, S, or O.

[0265] Although the preceding description has primarily described devices including PDJQHWLF^PDWHULDOV^WKDW^LQFOXGH^ĮƎ-Fe16(PxZ1-x)2 or a mixture of ĮƎ-Fe16P2 DQG^ĮƎ-Fe16Z2, in VRPH^H[DPSOHV^^WKH^PDJQHWLF^PDWHULDOV^PD\^DGGLWLRQDOO\^RU^DOWHUQDWLYHO\^LQFOXGH^Įƍ-Fe8(PxZ1-x^^RU^D^PL[WXUH^RI^Įƍ-Fe83^DQG^Įƍ-Fe8Z. EXAMPLES EXAMPLE 1

[0266] FIG. 16 illustrates a starting Zener-ordering model of Fe16P2 unit cell for molecular dynamics (MD) relaxation. MD was used in estimation of the global minimum energy state of lattice structure of Į^-phase Fe16P2. All MD computational codes were developed within LAMMPS (Large-scale Atomic / Molecular Massively Parallel Simulation) MD framework (Sandia National Laboratories, Albuquerque, NM). Atomic visualization and rendering was made with Ovito (Ovito Gmbh, Darmstadt, Germany). The starting unit cell included a combination of two sublattice cells, a body-center-cubic (BCC) Fe unit cell and a second BCC P unit cell.Docket No.: 1008-365WO01 / 2023-285

[0267] The initial Fe16P2 unit cell was constructed using “Zena” ordering method with superimposed bcc-Fe and bcc-structures as illustrated in FIG 16. The body-center-tetragonal (bct) Įs-Fe16P2phase starting unit cell included eight tetragonally distorted bcc cells of Fe with P atoms occupying 2 of the 48 octahedral interstices so that the bcc-P unit cell had twice as large lattice constant as that of the bcc-Fe. The constructed Fe16P2initial lattice had cubic constant a=b=c=5.732 Å which was twice of the bcc-Fe lattice constant. For the atomic sample used in MD simulation, a 5u5u5 “Zena” units superlattice block was constructed. The simulation sample block consisted of total 2651 atoms including 2310 Fe atoms and 341 P atoms with the dimensions about 28.66 Å u28.66 Å u28.66 Å. Simulation was conducted under periodic boundary conditions in all three axis directions. Only the single Įs-phase unit cell in the center of the superlattice block was extracted for structure and energy analysis after energy minimization (EM) process. The starting BCC-Fe / P supercell structure had an atomic ratio 8:1, and was used for lattice relaxation to arrive at a BCT-Fe16P2 final structure.

[0268] $Q^Į^-Fe16P2crystal structure was successfully obtained by using (1) descending volume energy minimum search, and (2) Fe-P Modified Embedded-Atom Method (MEAM) potential, in MD calculations. Using MEAM potential may provide advantages over conventional EAM method by including the directionality of bonding and 2nd nearest neighbor interactions.

[0269] FIG. 17A illustrates a front view of a final unit cell including an Į^-Fe16P2 lattice resulting from a run of MD simulation performed on the starting unit cell of FIG. 16. FIG. 17B. illustrates an elevated view of the final unit cell of FIG. 17A. FIG. 17C illustrates a perspective view of the final unit cell of FIG. 17A. FIG. 18A illustrates a front view showing selected inter-atomic distances in the final unit cell of FIG. 17A. FIG. 18B illustrates a perspective view showing selected inter-atomic distances in the final unit cell of FIG. 18A. The lattice parameters were a=b=5.556 Ⴒ and c=8.007 Ⴒ, and the nearest Fe-P neighboring distances were: Fe(4e)-P 2.207 Ⴒ, Fe(8h)-P 2.186 Ⴒ, and Fe(4d)-P 3.428 Ⴒ.

[0270] FIGS 17A, 17B, and 17C show the Fe-P bond length at three Fe-atom Wyckoff sites for the lowest energy lattice. The ranking of bond length between P-atom and the nearest neighbor atoms Fe(4e), Fe(4d) and Fe(8h) Were similar to that in Fe16N2 or Fe16C2: Fe(4d)-P > Fe(8h)-P > Fe(4e)-P. All three types of Fe-P bond length were significantly longer than their counterparts in Fe16N2 or Fe16C2: Fe(4e)-P bond length was 2.207 Å (increased by 21%), Fe(8h)-P bond length is 2.186 Å was (increased by 14%) and Fe(4d)-P bond length was 3.428 Å (increased by 5%), as compared to Fe(4e)-N, Fe(8h)-N and Fe(4d)-N respectively. The unitDocket No.: 1008-365WO01 / 2023-285 cell volume of Fe16P2 was also increased by 21% compared to that of Fe16N2.

[0271] A second run was performed. In the second run, the lattice parameters were a=b=5.610 Ⴒ, c=7.894 Ⴒ and the nearest Fe-P neighboring distances were Fe(4e)-P 2.207 Ⴒ, Fe(8h)-P 2.186 Ⴒ, and Fe(4d)-P 3.430 Ⴒ. COMPARATIVE EXAMPLE 1

[0272] FIG. 19A illustrates a front view of a final unit cell including an Į^-Fe16N2lattice resulting from a run of MD simulation performed on a starting unit cell similar to FIG. 16 in which P is replaced with N. FIG. 19B illustrates an elevated view of the final unit cell of FIG. 19A. The lattice parameters were a=b=5.742 Ⴒ, c=6.32 Ⴒ, and the nearest Fe-N neighboring distances were: Fe(4e)-N 1.817 Ⴒ, Fe(8h)-N 1.918 Ⴒ, and Fe(4d)-N 3.263 Ⴒ.

[0273] Compared to Fe16N2 of COMPARATIVE EXAMPLE 1, BCT-Fe16P2 of EXAMPLE 1 had a higher c / a ratio at 1.41-1.48 vs. 1.1, and also increased Fe-P nearest neighbor displacement, at the following Wyckoff positions: Fe(4e)-P (+21%), Fe(4d)-P (+5%) and Fe(8h)-P (+11-13%). Thus, the BCT-Fe16P2 atomic structure exhibited significantly increased Fe-P bond length in all Fe(4e), Fe(4d) and Fe(8h) positions and tetragonal distortion c / a ratio was also much higher than Fe16N2. Fe16P2 may provide a favorable configuration for high saturation magnetic moment and higher magnetic anisotropy energy. Without wishing to be bound by theory, such a large increase in Fe(4e)-P and Fe(8h)-P distance may help enhance Fe (4e, 8h and 4d) magnetic moment by reduction of hybridization from 3p orbit of Phosphorous (3s23p3). The increased Fe-P distance observation is consistent with the larger equilibrium bond length of Fe-P than Fe-N based on MEAM potential. EXAMPLE 2

[0274] FIG. 20A is a chart illustrating a calculated relationship between bond energy (interatomic potentials) and interatomic distance between pairs of Fe-P, Fe-N, and Fe-Fe atoms calculated using MEAM potentials. FIG. 20B is a chart illustrating a calculated relationship between atomic force and interatomic distance between pairs of Fe-P, Fe-N, and Fe-Fe atoms calculated using MEAM potentials.

[0275] Fe-P atom bonds had longer equilibrium bond length around ~1.96 Å which was much longer than Fe-N bond length of around 1.58 Å. To achieve balanced ground state lattice structure, it is then expected the neighboring Fe-P atoms to have longer displacement, which is consistent with the Fe-P distances in EXAMPLE 1.Docket No.: 1008-365WO01 / 2023-285 EXAMPLE 3

[0276] FIG. 21 is a chart illustrating an energy minimization (EM) process leading to the ground state of BCT crystal lattice in an MD simulation. Vmaxis the allowed volume change of the lattice structure in each EM process. By reducing Vmaxat a smaller step (i.e., halved the previous volume), the lattice relaxation process the best EM trajectory leading to the best- balanced crystal lattice structure was found, as shown for Vmaxat 0.00976% (first run) and 0.00488% (second run) in EXAMPLE 1 respectively.

[0277] As shown in FIG. 21, the EM search process was divided into a series of continuous EM cycles. At each of the MD cycles, the simulation box was relaxed to find a local cohesive minimum by allowing the current maximum confining lattice volume Vmax as a fraction (e.g., 50%) of the Vmax used in last MD cycle, so that a “global” minimum energy state could be determined among this series of local energy minimal corresponding to each of the Vmaxvalue. To ensure the simulation stability, typical Vmaxvalue should be no more than ~10%. The starting Vmax = 12.5% was used in this work and Vmax continues to decrease by 50% at each of the following relaxation steps. Zero lattice strain was used during the lattice relaxation process.

[0278] The formation energy (Ef), the difference between the energy of the super cell and energy sum of each atom in its own state, was calculated through EM process using EQUATION 1:(Equation 1)

[0279] Ef is expressed in terms of the per-atom average in the MD process and obtained by subtracting the summation of Fe and P atomic energy, ^ி^and ^^from the center unit cell total energy ^௨^^௧.

[0280] FIG. 21 shows the series of energy minimal converged from the described lattice relaxation process vs. Vmaxparameter in log scale. The resulted primitive unit cell examples were inserted for the corresponding Vmax values. Three different regions of Vmax range were observed in terms of Vmax values. First, when confined volume change Vmax > 1% although the formation energy minimal were relatively lower, the resulted lattice structures were rather random and far from an ideal Įsstructure. In the second region where 0.03%<Vmax<1%, the obtained lattices were much closer to an ideal Įs structure. In the last region of Vmax> 0.03%, the confined volumes were so small that the atoms were “rigid” during the relaxation process and yielded unit lattices had no significant change from the starting lattice. Therefore, the Vmax range in the second region provided more reasonable energy minimization results toDocket No.: 1008-365WO01 / 2023-285 reach to an ideal Įs structure. The most stable structure with the lowest energy minimum in the second region is with Vmax=0.976%, at which a perfect bct symmetry Įs structure resulted and its lattice constants were a=b=5.556 Å and c=8.007 Å, and c / a ratio of 1.44. The corresponding calculated Ef atom was -4.593 eV. EXAMPLE 4

[0281] FIG. 22 illustrates changes in simulated lattice structures in an EM process from a starting BCC-supercell structure to a BCT- Į^^VWUXFWXUH^DW^LQWHUYDOV^RYHU^D^0'^WLPH^RI^ 15000 femtoseconds, with Vmax=0.976%. FIG. 23 is a chart illustrating energy minimization process in the process of FIG. 22. At the end of the EM process, when lattice energy and lattice force change are both smaller than the tolerance (e.g., 1e-10), the lattice state is said to be the low energy state at the Vmaxlevel.

[0282] At Vmax=0.489%, another perfect Įs structure was also reached withÅ and c= 7.894 Å with c / a ratio of 1.41. Both c / a ratios were much higher than Fe16N2. The corresponding calculated Ef atom is -4.590 eV, compared to previous values of Ef -5.28 eV to - 5.54 eV of Fe16N2and -5.51 eV to -5.92 eV of Fe16C2. These energies and lattice constants are compared to the published values of the well-known bct as magnetic crystals Fe16N2 and Fe16C2, and are listed in TABLE 1.Table 1 EXAMPLE 5

[0283] A density functional theory (DFT) simulation was performed. Electronic structure calculations were performed using the plane-wave “pwscf ” code from the Quantum ESPRESSO package. GGA exchange-correlation functional and Projector-Augmented WaveDocket No.: 1008-365WO01 / 2023-285 (PAW) pseudopotentials (PP) taken from the QE PSlibrary, were used throughout. Scalar- relativistic or fully-relativistic PP variants were employed as necessary. Calculations were performed with kinetic energy cutoff of 90 Ry (~ 1200 eV); the Brillouin zone was sampled via the Monkhorst-Pack scheme with a 6 î 6 î 6 grid, with Marzari-Vanderbilt cold smearing of width 0.07 eV. In structural relaxations, the unit cell’s volume, shape, and atomic positions were allowed to relax within a scalar-relativistic approach, neglecting spin-orbit coupling (SOC), until atomic forces were below 0.025 eV / Å and stress tensor elements below 0.5 kbar (0.05 GPa).

[0284] To estimate relative stability, the electronic ground state energy was compared DJDLQVW^WKH^H[SHFWHG^FRQYH[^KXOO^^L^H^^¨EC= E[Fe16P2] – m E[X] – n E[Y] for neighboring compositions X, Y in the appropriate ratios to match the composition of 8:1 Fe:P. (Both X,Y = Fe, Fe3P and Fe, Fe4P were considered; all compounds’ ground state energies were taken from relaxed structures.)

[0285] MCA energy calculations were performed on the relaxed structures, with k-point PHVK^GHQVLW\^LQFUHDVHG^WR^^^^î^^^^î^^^^^DQG^62&^WHUPV^^DQG^IXOO\-relativistic PP) included. The MCA energy was calculated as the difference in total energy between states with magnetization along the easy (001) and hard (100) directions, i.e. ǻEMCA = E(100) – E(001), scaled to the conventional unit cell.

[0286] FIG. 24 illustrates a relaxed structure of BCT Fe16P2at the end of the DFT simulation run. The initial structure, based on that of Fe16N2, relaxed to a BCT configuration with a = 5.84 Å, c = 6.64 Å (c / a = 1.137).(fcc, analogous to existing Fe4N) suggested Fe16P2to be more stable. EXAMPLE 6

[0287] The MD-optimized lattice structure of the first run of EXAMPLE 1 had a smaller a and a larger c than the structure obtained by DFT. The MD-optimized structure (as well as several previous intermediate structures with more broken symmetry) were imported and re-relaxed under DFT.

[0288] FIG. 25A illustrates a Fe16P2triclinic variant structure obtained by DFT simulation. FIG. 25B illustrates a Fe16P2 iron-nitride-like variant structure obtained by DFT simulation. FIG. 25C illustrates a Fe16P2 body centered orthorhombic variant structure obtained by DFT simulation. FIG. 25D illustrates a Fe16P2variant structure obtained by DFT simulation that is similar to another structure obtained by MD simulation.Docket No.: 1008-365WO01 / 2023-285

[0289] The resulting structures had the following order of increasing stability (as determined by lower ground state energy): 1. A similar high-c / a BCT structure (a = 5.27 Å, c = 8.23 Å; c / a = 1.56) (FIG. 25D) 2. A body-centered orthorhombic structure (a = 4.95 Å, b = 5.98 Å, c = 7.68 Å) (FIG. 25C) 3. The original, moderate-c / a BCT structure (a = 5.84 Å, c = 6.64 Å; c / a = 1.137) (FIG. 25B) 4. A triclinically distorted structure, with P no longer body-centered (a = b = 5.16 Å, c = 8.43 Å; angles 100.7º in ab-plane, 85.2º to c-axis) (FIG. 25A)

[0290] All 4 of these structures have a smaller unit cell volume than the MD-relaxed structure (~220 Å3compared to ~240 Å3).

[0291] The differences between DFT and MD simulations may arise from DFT not reflecting localized electronic behavior in a cluster (Fe6P)-atom (Fe) physical model.

[0292] When ranges are used herein for physical properties, such as molecular weight, or chemical properties, such as chemical formulae, all combinations and subcombinations of ranges for specific examples therein are intended to be included.

[0293] The following enumerated clauses describe examples according to the present disclosure.

[0294] Clause 1: A soft magnetic material includLQJ^DW^OHDVW^RQH^RI^DQ^Į^-Fe16(PxZ1-x)2GRPDLQ^RU^DQ^Įƍ-Fe8(PxZ1-x) phase domain, where Z includes at least one of C, B, Al, Si, S, or O, and where x is a number greater than zero and less than one.

[0295] Clause 2: The soft magnetic material of clause 1, where x is equal to about 0.5.

[0296] Clause 3: The soft magnetic material of clause 2, where x is equal to 0.5.

[0297] Clause 4: The soft magnetic material of any of clauses 1 to 3, where Z consists of C.

[0298] Clause 5: The soft magnetic material of clause 4, where the phase domain HVVHQWLDOO\^FRQVLVWV^RI^Į´- Fe16PC.

[0299] Clause 6: The soft magnetic material of any of clauses 1 to 5, where the at least one of the Į^-Fe16(PxZ1-x)2 SKDVH^GRPDLQ^RU^WKH^Įƍ-Fe8(PxZ1-x) phase domain includes a SOXUDOLW\^RI^DW^OHDVW^RQH^RI^Į^-Fe16(PxZ1-x)2 FU\VWDOV^RU^Įƍ-Fe8(PxZ1-x) crystals, and where respective

[0001] axes of the plurality of crystals are randomly distributed within the soft magnetic material.Docket No.: 1008-365WO01 / 2023-285

[0300] Clause 7: The soft magnetic material of any of clauses 1 to 6, further including at OHDVW^RQH^RI^DQ^ĮƎ-Fe16P2 SKDVH^GRPDLQ^^DQ^ĮƎ-Fe16Z2 SKDVH^GRPDLQ^^DQ^Įƍ-Fe8P phase GRPDLQ^^RU^DQ^Įƍ-Fe8Z phase domain.

[0301] Clause 8: The soft magnetic material of any of clauses 1 to 7, where WKH^Į^- Fe16(PxZ1-x)2 phase domain includes body centered tetragonal (BCT) unit cells or variants thereof.

[0302] Clause 9: The soft magnetic material of any of clauses 1 to 8, where at least about ^^^YROXPH^SHUFHQW^RI^WKH^VRIW^PDJQHWLF^PDWHULDO^LV^WKH^DW^OHDVW^RQH^RI^WKH^ĮƎ-Fe16(PxZ1-x)2 SKDVH^GRPDLQ^RU^WKH^Įƍ-Fe8(NxZ1-x) phase domain.

[0303] Clause 10: The soft magnetic material of clause 9, where at least about 60 volume SHUFHQW^RI^WKH^VRIW^PDJQHWLF^PDWHULDO^LV^WKH^DW^OHDVW^RQH^RI^WKH^ĮƎ-Fe16(PxZ1-x)2 phase domain RU^WKH^Įƍ-Fe8(NxZ1-x) phase domain.

[0304] Clause 11: A soft magnetic material including a phospho-carbon-ferrous domain including a plurality of Fe6P clusters and a plurality of Fe6C clusters.

[0305] Clause 12: The soft magnetic material of clause 11, where each cluster of the plurality of Fe6P clusters includes P at a geometric center of a respective octahedral arrangement of Fe, and where each cluster of the plurality of Fe6C clusters includes C at a geometric center of a respective octahedral arrangement of Fe.

[0306] Clause 13: The soft magnetic material of any of clauses 1 to 12, where the soft magnetic material is free of neodymium (Nd).

[0307] Clause 14: The soft magnetic material of clause 13, where the soft magnetic material is free of any rare-earth element.

[0308] Clause 15: The soft magnetic material of any of clauses 1 to 14, further including a dopant.

[0309] Clause 16: The soft magnetic material of clause 15, where the dopant includes at least one of Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, Pt, Au, Sm, C, Pb, W, Ga, Y, Mg, Hf, Ge, Al, or Ta.

[0310] Clause 17: The soft magnetic material of any of clauses 1 to 16, further including a phase stabilizer.

[0311] Clause 18: The soft magnetic material of clause 17, where the phase stabilizer includes at least one of B, Al, C, Si, O, Co, Cr, Mn, Ti, V, or S.

[0312] Clause 19: The soft magnetic material of any of clauses 1 to 18, where the soft magnetic material has a saturation magnetization of at least about 200 emu / gram.Docket No.: 1008-365WO01 / 2023-285

[0313] Clause 20: The soft magnetic material of any of clauses 1 to 19, where the soft magnetic has a magnetic coercivity of less than or equal to about 10 Oersteds.

[0314] Clause 21: A method including forming the soft magnetic material of any of clauses 1 to 20.

[0315] Clause 22: The method of clause 21, where forming the soft magnetic material includes physical vapor deposition from at least one of a C-doped, B-doped, Al-doped, Si- doped, S-doped, or O-doped iron source to form a layer including Fe, P, and at least one of C, B, Al, Si, S, or O over a substrate.

[0316] Clause 23: The method of clause 22, where the iron source includes between about 1 atomic percent (at. %) and about 10 at. % of any of C, B, Al, Si, S, O, or P.

[0317] Clause 24: The method of clauses 22 or 23, where physical vapor deposition includes forming a phosphorus plasma to provide a source of P atoms.

[0318] Clause 25: The method of any of clauses 22 to 24, further including annealing the layer at a temperature between about 100° C and about 210° C for between about 5 hours and about 100 hours.

[0319] Clause 26: The method of clause 21, where forming the soft magnetic material includes depositing the soft magnetic material over a substrate using at least one of chemical vapor deposition, molecular beam epitaxy, low temperature epitaxy, liquid phase epitaxy, or ion implantation.

[0320] Clause 27: The method of clause 21, where forming the soft magnetic material includes: straining an iron workpiece including at least one iron crystal in a direction substantially parallel to a <001> crystal axis of the iron crystal; phosphorizing and carbonizing the iron workpiece to form a phosphorized and carbonized iron wire or sheet; and annealing the phosphorized and carbonized iron workpiece to form the soft magnetic material.

[0321] Clause 28: The method of clause 21, where forming the soft magnetic material includes: implanting P and C atoms in an iron workpiece using ion implantation; pre- annealing the iron workpiece to attach the iron workpiece to a substrate; and annealing the iron workpiece to form the soft magnetic material.

[0322] Clause 29: The method of clause 21, where forming the soft magnetic material includes: heating an iron source to form a vapor including an Fe-containing compound; depositing Fe from the vapor including the Fe-containing compound, P from a vapor including a P-containing compound, and at least one of C, B, Al, Si, S, or O from a vapor including the compound containing the at least one of C, B, Al, Si, S, or O over a substrate toDocket No.: 1008-365WO01 / 2023-285 form a layer including Fe, P, and the at least one of C, B, Al, Si, S, or O; and annealing the layer including Fe, P, and the at least one of C, B, Al, Si, S, or O to form the soft magnetic material.

[0323] Clause 30: The method of clause 21, where forming the soft magnetic material includes: heating an iron source to form a vapor including an Fe-containing compound; depositing Fe from the vapor including the Fe-containing compound and P from a vapor including a P-containing compound over a substrate to form a first layer including Fe and P; heating an iron source to form a vapor including an Fe-containing compound; depositing iron from the vapor including the Fe-containing compound and at least one of C, B, Al, Si, S, or O from a vapor including the at least one of C, B, Al, Si, S, or O over the substrate to form a second layer including iron and the at least one of C, B, Al, Si, S, or O; and annealing the first layer and the second layer to form the soft magnetic material.

[0324] Clause 31: The method of clause 21, where forming the soft magnetic material includes: submerging a substrate in a coating solution including a P-containing solvent, an iron source, and a carbon source, where the coating solution is saturated with the iron source at a first temperature above a liquidus temperature of an Fe-C-P mixture to be deposited from the coating solution; cooling the coating solution to a second temperature to form a supersaturated coating solution, where the second temperature is below the liquidus temperature of the Fe-C-P mixture; maintaining the substrate in the supersaturated coating solution to allow a coating including Fe, C, and P to form over the substrate; and annealing the coating including Fe, C, and P to form the soft magnetic material.

[0325] Clause 32: The method of clause 21, where forming the soft magnetic material includes: submerging a substrate in a first coating solution including a P-containing solvent and an iron source, where the first coating solution is saturated with the iron source at a first temperature above a liquidus temperature of an Fe-P mixture to be deposited from the first coating solution; cooling the first coating solution to a second temperature to form a supersaturated first coating solution, where the second temperature is below the liquidus temperature of the Fe-P mixture; maintaining the substrate in the supersaturated first coating solution to allow a first coating including Fe and P to form over the substrate; submerging the substrate in a second coating solution including a solvent, an iron source, and a compound containing at least one of C, B, Al, Si, S, or O, where the second coating solution is saturated with the iron source at a third temperature above a liquidus temperature of a mixture to be deposited from the second coating solution; cooling the second coating solution to a fourth temperature to form a supersaturated second coating solution, where the fourth temperature isDocket No.: 1008-365WO01 / 2023-285 below the liquidus temperature of the mixture; maintaining the substrate in the supersaturated second coating solution to allow a second coating including Fe, P, and the at least one of C, B, Al, Si, S, or O to form over the substrate; annealing the first coating and the second coating to form the soft magnetic material.

[0326] Clause 33: The method of clause 21, where forming the soft magnetic material includes: milling, in a bin of a milling apparatus, an Fe-containing raw material in the presence of a P source and a source of at least one of C, B, Al, Si, S, or O to generate a powder including Fe, P, and the at least one of C, B, Al, Si, S, or O; and annealing the powder to form the soft magnetic material.

[0327] Clause 34: The method of clause 21, where forming the soft magnetic material includes: milling, in a bin of a milling apparatus, an Fe-containing raw material in the presence of a P source to generate a first powder including Fe and P; annealing the first powder to form at least one phase domain including Į^-Fe16P2or at least one phase domain LQFOXGLQJ^Įƍ-Fe8P; milling, in a bin of a milling apparatus, an Fe-containing raw material in the presence of a source including at least one of C, B, Al, Si, S, or O to generate a second powder including Fe and the at least one of C, B, Al, Si, S, or O; annealing the second powder to form at least one phase domain including Į^-Fe16P2 or at least one phase domain LQFOXGLQJ^Įƍ-Fe8Z, where Z includes the at least one of C, B, Al, Si, S, or O; and consolidating the first powder and the second powder to form the soft magnetic material.

[0328] Clause 35: The method of clause 21, where forming the magnetic material includes: heating a mixture including iron and phosphorus to form a molten iron phosphorus- containing material; and solidifying the molten iron phosphorus-containing material to form a workpiece including at least one Fe16P2phase domain.

[0329] Clause 36: The method of clause 21, where forming the magnetic material includes: forming the soft magnetic material by a technique including melt spinning.

[0330] Clause 37: The method of clause 36, where forming the soft magnetic material by the technique including melt spinning includes: forming a molten mixture including Fe and C; melt spinning the molten mixture including Fe and C to form Fe-C ribbons; and phosphorizing the iron-carbon ribbons to form an Fe-C-P material.

[0331] Clause 38: The method of clause 36, where forming the soft magnetic material by the technique including melt spinning includes: forming a molten mixture including Fe and C; melt spinning the molten mixture including Fe and C to form Fe-C ribbons; ball milling the Fe-C ribbons to form Fe-C powder; and phosphorizing the Fe-C powder.Docket No.: 1008-365WO01 / 2023-285

[0332] Clause 39: The method of clause 36, where forming the soft magnetic material by the technique including melt spinning includes: forming a molten mixture including Fe; melt spinning the molten mixture including Fe to form Fe ribbons; and carburizing and phosphorizing the Fe ribbons to form an Fe-C-P material.

[0333] Clause 40: The method of clause 36, where forming the soft magnetic material by the technique including melt spinning includes: forming a molten mixture including Fe and P; melt spinning the molten mixture including Fe and P to form Fe-P ribbons; and carburizing the Fe-P ribbons to form an Fe-C-P material.

[0334] Clause 41: The method of clause 36, where forming the soft magnetic material by the technique including melt spinning includes: forming a molten mixture including Fe, C, and P; melt spinning the molten mixture including Fe, C, and P to form Fe-C-P ribbons; and phosphorizing the Fe-C-P ribbons to form an Fe-C-P material.

[0335] Clause 42: The method of any of clauses 36 to 41, further including: assembling a plurality of the soft magnetic materials to form a bulk soft magnetic material.

[0336] Clause 43: The method of clause 21, where forming the soft magnetic material includes: annealing a material including Fe, P, and at least one of C, B, Al, Si, S, or O in the presence of an applied magnetic field.

[0337] Clause 44: The method of clause 43, where the applied magnetic field has a strength of at least about 0.2 Tesla (T).

[0338] Clause 45: The method of clause 21, where forming the soft magnetic material includes: compacting a plurality of nanoparticles including Fe16(PC)2 or Fe16(PC).

[0339] Clause 46: The method of clause 21, where forming the magnetic material includes: compacting a first composition including Fe, P and a second composition including at least one of C, B, Al, Si, S, or O to generate nanoparticles including Fe, P and at least one of C, B, Al, Si, S, or O by a chemical reaction process.

[0340] Clause 47: The method of clauses 45 or 46, where an average maximum major dimension of the nanoparticles is in a range of 5 nm to 100 nm.

[0341] Various examples have been described. Those skilled in the art will appreciate that numerous changes and modifications can be made to the examples described in this disclosure and that such changes and modifications can be made without departing from the spirit of the disclosure. These and other examples are within the scope of the following claims.

Claims

Docket No.: 1008-365WO01 / 2023-285 CLAIMS What is claimed is:

1. A soft magnetic material comprising at least one of an Į^-Fe16(PxZ1-x)2 domain or an Įƍ-Fe8(PxZ1-x) phase domain, wherein Z includes at least one of C, B, Al, Si, S, or O, and wherein x is a number greater than zero and less than one.

2. The soft magnetic material of claim 1, wherein x is equal to about 0.

5.

3. The soft magnetic material of claim 2, wherein x is equal to 0.

5.

4. The soft magnetic material of claim 1, wherein Z consists of C.

5. The soft magnetic material of claim 4, wherein the phase domain essentially consists RI^Į´- Fe16PC.

6. The soft magnetic material of claim 1, wherein the at least one of the Į^-Fe16(PxZ1-x)2 SKDVH^GRPDLQ^RU^WKH^Įƍ-Fe8(PxZ1-x) SKDVH^GRPDLQ^FRPSULVHV^D^SOXUDOLW\^RI^DW^OHDVW^RQH^RI^Į^- Fe16(PxZ1-x)2FU\VWDOV^RU^Įƍ-Fe8(PxZ1-x) crystals, and wherein respective [001] axes of the plurality of crystals are randomly distributed within the soft magnetic material.

7. The soft magnetic material of FODLP^^^^IXUWKHU^FRPSULVLQJ^DW^OHDVW^RQH^RI^DQ^ĮƎ-Fe16P2SKDVH^GRPDLQ^^DQ^ĮƎ-Fe16Z2 SKDVH^GRPDLQ^^DQ^Įƍ-Fe83^SKDVH^GRPDLQ^^RU^DQ^Įƍ-Fe8Z phase domain.

8. The soft magnetic material of claim 1, ZKHUHLQ^WKH^Į^-Fe16(PxZ1-x)2 phase domain comprises body centered tetragonal (BCT) unit cells or variants thereof.

9. The soft magnetic material of claim 1, wherein at least about 35 volume percent of the VRIW^PDJQHWLF^PDWHULDO^LV^WKH^DW^OHDVW^RQH^RI^WKH^ĮƎ-Fe16(PxZ1-x)2 SKDVH^GRPDLQ^RU^WKH^Įƍ- Fe8(NxZ1-x) phase domain.Docket No.: 1008-365WO01 / 2023-285 10. The soft magnetic material of claim 9, wherein at least about 60 volume percent of the VRIW^PDJQHWLF^PDWHULDO^LV^WKH^DW^OHDVW^RQH^RI^WKH^ĮƎ-Fe16(PxZ1-x)2 SKDVH^GRPDLQ^RU^WKH^Įƍ- Fe8(NxZ1-x) phase domain.

11. The soft magnetic material of claim 1, wherein the soft magnetic material is free of neodymium (Nd).

12. The soft magnetic material of claim 11, wherein the soft magnetic material is free of any rare-earth element.

13. The soft magnetic material of claim 1, further comprising a dopant.

14. The soft magnetic material of claim 13, wherein the dopant comprises at least one of Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, Pt, Au, Sm, C, Pb, W, Ga, Y, Mg, Hf, Ge, Al, or Ta.

15. The soft magnetic material of claim 1, further comprising a phase stabilizer.

16. The soft magnetic material of claim 15, wherein the phase stabilizer comprises at least one of B, Al, C, Si, O, Co, Cr, Mn, Ti, V, or S.

17. The soft magnetic material of claim 1, wherein the soft magnetic material has a saturation magnetization of at least about 200 emu / gram.

18. The soft magnetic material of claim 1, wherein the soft magnetic has a magnetic coercivity of less than or equal to about 10 Oersteds.

19. A soft magnetic material comprising a phospho-carbon-ferrous domain comprising a plurality of Fe6P clusters and a plurality of Fe6C clusters.

20. The soft magnetic material of claim 19, wherein each cluster of the plurality of Fe6P clusters comprises P at a geometric center of a respective octahedral arrangement of Fe, and wherein each cluster of the plurality of Fe6C clusters comprises C at a geometric center of a respective octahedral arrangement of Fe.Docket No.: 1008-365WO01 / 2023-285 21. The soft magnetic material of claim 19, wherein the soft magnetic material is free of neodymium (Nd).

22. The soft magnetic material of claim 21, wherein the soft magnetic material is free of any rare-earth element.

23. The soft magnetic material of claim 19, further comprising a dopant.

24. The soft magnetic material of claim 23, wherein the dopant comprises at least one of Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, Pt, Au, Sm, C, Pb, W, Ga, Y, Mg, Hf, Ge, Al, or Ta.

25. The soft magnetic material of claim 19, further comprising a phase stabilizer.

26. The soft magnetic material of claim 25, wherein the phase stabilizer comprises at least one of B, Al, C, Si, O, Co, Cr, Mn, Ti, V, or S.

27. The soft magnetic material of claim 19, wherein the soft magnetic material has a saturation magnetization of at least about 200 emu / gram.

28. The soft magnetic material of claim 19, wherein the soft magnetic has a magnetic coercivity of less than or equal to about 10 Oersteds.

29. A method comprising forming the soft magnetic material of any one of claims 1 to 28.

30. The method of claim 29, wherein forming the soft magnetic material comprises physical vapor deposition from at least one of a C-doped, B-doped, Al-doped, Si-doped, S- doped, or O-doped iron source to form a layer comprising Fe, P, and at least one of C, B, Al, Si, S, or O over a substrate.

31. The method of claim 30, wherein the iron source comprises between about 1 atomic percent (at. %) and about 10 at. % of any of C, B, Al, Si, S, O, or P.Docket No.: 1008-365WO01 / 2023-285 32. The method of claim 30, wherein physical vapor deposition comprises forming a phosphorus plasma to provide a source of P atoms.

33. The method of claim 32, further comprising annealing the layer at a temperature between about 100° C and about 210° C for between about 5 hours and about 100 hours.

34. The method of claim 29, wherein forming the soft magnetic material comprises depositing the soft magnetic material over a substrate using at least one of chemical vapor deposition, molecular beam epitaxy, low temperature epitaxy, liquid phase epitaxy, or ion implantation.

35. The method of claim 29, wherein forming the soft magnetic material comprises: straining an iron workpiece comprising at least one iron crystal in a direction substantially parallel to a <001> crystal axis of the iron crystal; phosphorizing and carbonizing the iron workpiece to form a phosphorized and carbonized iron wire or sheet; and annealing the phosphorized and carbonized iron workpiece to form the soft magnetic material.

36. The method of claim 29, wherein forming the soft magnetic material comprises: implanting P and C atoms in an iron workpiece using ion implantation; pre-annealing the iron workpiece to attach the iron workpiece to a substrate; and annealing the iron workpiece to form the soft magnetic material.

37. The method of claim 29, wherein forming the soft magnetic material comprises: heating an iron source to form a vapor comprising an Fe-containing compound; depositing Fe from the vapor comprising the Fe-containing compound, P from a vapor comprising a P-containing compound, and at least one of C, B, Al, Si, S, or O from a vapor comprising the compound containing the at least one of C, B, Al, Si, S, or O over a substrate to form a layer comprising Fe, P, and the at least one of C, B, Al, Si, S, or O; and annealing the layer comprising Fe, P, and the at least one of C, B, Al, Si, S, or O to form the soft magnetic material.Docket No.: 1008-365WO01 / 2023-285 38. The method of claim 29, wherein forming the soft magnetic material comprises: heating an iron source to form a vapor comprising an Fe-containing compound; depositing Fe from the vapor comprising the Fe-containing compound and P from a vapor comprising a P-containing compound over a substrate to form a first layer comprising Fe and P; heating an iron source to form a vapor comprising an Fe-containing compound; depositing iron from the vapor comprising the Fe-containing compound and at least one of C, B, Al, Si, S, or O from a vapor comprising the at least one of C, B, Al, Si, S, or O over the substrate to form a second layer comprising iron and the at least one of C, B, Al, Si, S, or O; and annealing the first layer and the second layer to form the soft magnetic material.

39. The method of claim 29, wherein forming the soft magnetic material comprises: submerging a substrate in a coating solution comprising a P-containing solvent, an iron source, and a carbon source, wherein the coating solution is saturated with the iron source at a first temperature above a liquidus temperature of an Fe-C-P mixture to be deposited from the coating solution; cooling the coating solution to a second temperature to form a supersaturated coating solution, wherein the second temperature is below the liquidus temperature of the Fe-C-P mixture; maintaining the substrate in the supersaturated coating solution to allow a coating comprising Fe, C, and P to form over the substrate; and annealing the coating comprising Fe, C, and P to form the soft magnetic material.

40. The method of claim 29, wherein forming the soft magnetic material comprises: submerging a substrate in a first coating solution comprising a P-containing solvent and an iron source, wherein the first coating solution is saturated with the iron source at a first temperature above a liquidus temperature of an Fe-P mixture to be deposited from the first coating solution; cooling the first coating solution to a second temperature to form a supersaturated first coating solution, wherein the second temperature is below the liquidus temperature of the Fe- P mixture; maintaining the substrate in the supersaturated first coating solution to allow a first coating comprising Fe and P to form over the substrate;Docket No.: 1008-365WO01 / 2023-285 submerging the substrate in a second coating solution comprising a solvent, an iron source, and a compound containing at least one of C, B, Al, Si, S, or O, wherein the second coating solution is saturated with the iron source at a third temperature above a liquidus temperature of a mixture to be deposited from the second coating solution; cooling the second coating solution to a fourth temperature to form a supersaturated second coating solution, wherein the fourth temperature is below the liquidus temperature of the mixture; maintaining the substrate in the supersaturated second coating solution to allow a second coating comprising Fe, P, and the at least one of C, B, Al, Si, S, or O to form over the substrate; annealing the first coating and the second coating to form the soft magnetic material.

41. The method of claim 29, wherein forming the soft magnetic material comprises: milling, in a bin of a milling apparatus, an Fe-containing raw material in the presence of a P source and a source of at least one of C, B, Al, Si, S, or O to generate a powder including Fe, P, and the at least one of C, B, Al, Si, S, or O; and annealing the powder to form the soft magnetic material.

42. The method of claim 29, wherein forming the soft magnetic material comprises: milling, in a bin of a milling apparatus, an Fe-containing raw material in the presence of a P source to generate a first powder including Fe and P; annealing the first powder to form at least one phase domain including Į^-Fe16P2or at OHDVW^RQH^SKDVH^GRPDLQ^LQFOXGLQJ^Įƍ-Fe8P; milling, in a bin of a milling apparatus, an Fe-containing raw material in the presence of a source including at least one of C, B, Al, Si, S, or O to generate a second powder including Fe and the at least one of C, B, Al, Si, S, or O; annealing the second powder to form at least one phase domain including Į^-Fe16P2 or DW^OHDVW^RQH^SKDVH^GRPDLQ^LQFOXGLQJ^Įƍ-Fe8Z, where Z includes the at least one of C, B, Al, Si, S, or O; and consolidating the first powder and the second powder to form the soft magnetic material.Docket No.: 1008-365WO01 / 2023-285 43. The method of claim 29, wherein forming the magnetic material comprises: heating a mixture including iron and phosphorus to form a molten iron phosphorus- containing material; and solidifying the molten iron phosphorus-containing material to form a workpiece including at least one Fe16P2 phase domain.

44. The method of claim 29, wherein forming the magnetic material comprises: forming the soft magnetic material by a technique comprising melt spinning.

45. The method of claim 44, wherein forming the soft magnetic material by the technique comprising melt spinning comprises: forming a molten mixture comprising Fe and C; melt spinning the molten mixture comprising Fe and C to form Fe-C ribbons; and phosphorizing the iron-carbon ribbons to form an Fe-C-P material.

46. The method of claim 44, wherein forming the soft magnetic material by the technique comprising melt spinning comprises: forming a molten mixture comprising Fe and C; melt spinning the molten mixture comprising Fe and C to form Fe-C ribbons; ball milling the Fe-C ribbons to form Fe-C powder; and phosphorizing the Fe-C powder.

47. The method of claim 44, wherein forming the soft magnetic material by the technique comprising melt spinning comprises: forming a molten mixture comprising Fe; melt spinning the molten mixture comprising Fe to form Fe ribbons; and carburizing and phosphorizing the Fe ribbons to form an Fe-C-P material.

48. The method of claim 44, wherein forming the soft magnetic material by the technique comprising melt spinning comprises: forming a molten mixture comprising Fe and P; melt spinning the molten mixture comprising Fe and P to form Fe-P ribbons; and carburizing the Fe-P ribbons to form an Fe-C-P material.Docket No.: 1008-365WO01 / 2023-285 49. The method of claim 44, wherein forming the soft magnetic material by the technique comprising melt spinning comprises: forming a molten mixture comprising Fe, C, and P; melt spinning the molten mixture comprising Fe, C, and P to form Fe-C-P ribbons; and phosphorizing the Fe-C-P ribbons to form an Fe-C-P material.

50. The method of claim 44, further comprising: assembling a plurality of the soft magnetic materials to form a bulk soft magnetic material.

51. The method of claim 29, wherein forming the soft magnetic material comprises: annealing a material including Fe, P, and at least one of C, B, Al, Si, S, or O in the presence of an applied magnetic field.

52. The method of claim 51, wherein the applied magnetic field has a strength of at least about 0.2 Tesla (T).

53. The method of claim 29, wherein forming the soft magnetic material comprises: compacting a plurality of nanoparticles comprising Fe16(PC)2or Fe16(PC).

54. The method of claim 29, wherein forming the magnetic material comprises: compacting a first composition comprising Fe, P and a second composition comprising at least one of C, B, Al, Si, S, or O to generate nanoparticles comprising Fe, P and at least one of C, B, Al, Si, S, or O by a chemical reaction process.

55. The method of claim 53, wherein an average maximum major dimension of the nanoparticles is in a range of 5 nm to 100 nm.

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