Materials with both negative spin polarization and negative anisotropy

Abstract

The present invention is entitled "Material Having Both Negative Spin Polarization and Negative Anisotropy." Aspects of the present disclosure generally relate to spintronic devices for use in magnetic media drives, magnetoresistive random access memory devices, magnetic sensors, or magnetic recording write heads. The spintronic device includes a multilayer structure having a negative anisotropy field and a negative spin polarization. The multilayer structure includes a plurality of layers, each of the plurality of layers including a first sublayer comprising Fe and a second sublayer comprising Co. At least one of the first sublayer and the second sublayer comprises one or more of Cr, V, and Ti. The first sublayers and the second sublayers alternate. The negative anisotropy field of the multilayer structure is between about -0.5 T and about -0.8 T, and the effective magnetization of the multilayer structure is between about 2.4 T and about 2.8 T.

Description

Background Art Technical Field

[0001] Embodiments of the present disclosure generally relate to multilayer materials with negative spin polarization and negative anisotropy for use in spintronic devices.

[0002] Description of related art

[0003] In spintronic devices or spin-electronic devices, such as sensors used in magnetic recording heads, both spin polarization and anisotropy fields play an important role. For example, such spin-electronic devices can be used in spin-orbit torque (SOT) magnetic tunnel junction (MTJ) applications, such as spin Hall layers for energy-assisted magnetic recording write heads and magnetoresistive random access memory (MRAM) devices. The materials used in these spin-electronic devices generally have: (1) positive spin polarization without anisotropy fields, such as CoFe, Co, Ni, and CoMnGe, (2) positive spin polarization and negative anisotropy fields, such as CoFe multilayer structures, (3) negative spin polarization without anisotropy fields, such as FeCr, FeV, and FeN, or (4) both positive spin polarization and positive anisotropy fields, such as CoNi, CoPt, CoPd, and Mn3Ga. Since there are no reported materials with negative spin polarization and negative anisotropy fields, spin-electronic devices generally have fewer degrees of freedom and are subject to greater restrictions.

[0004] Therefore, there is a need in the art for materials having both negative spin polarization and negative anisotropy field for use in spintronic devices. Summary of the Invention

[0005] Aspects of the present disclosure are generally directed to a spintronic device for use in a magnetic media drive, a magnetoresistive random access memory device, a magnetic sensor, or a magnetic recording write head. The spintronic device includes a multilayer structure having a negative spin polarization and a negative anisotropy field. The multilayer structure includes a plurality of layers, each of the plurality of layers including a first sublayer comprising Fe and a second sublayer comprising Co. At least one of the first sublayer and the second sublayer comprises one or more of Cr, V, and Ti. The first sublayer and the second sublayer alternate. The negative anisotropy field of the multilayer structure is between about -0.5 T and about -0.8 T, and the effective magnetization of the multilayer structure is between about 2.4 T and about 2.8 T.

[0006] In one embodiment, a spintronic device includes a multilayer structure having a negative spin polarization and a negative anisotropy field, the multilayer structure including a plurality of layers, each of the plurality of layers including a first sublayer including Fe and a second sublayer including Co, wherein at least one of the first sublayer and the second sublayer further includes one or more of Cr, V, and Ti. The first sublayers and the second sublayers alternate.

[0007] In another embodiment, a spin electronic device includes a substrate and a multilayer structure having a negative spin polarization and a negative anisotropy field disposed over the substrate, the multilayer structure including a plurality of alternating first and second layers. Each of the first layers includes Fe and one or more of Cr, V, and Ti, and each of the second layers includes Co. Each of the first layers has a first thickness that is greater than or equal to a second thickness of each of the second layers. The spin electronic device further includes a capping layer disposed over the multilayer structure.

[0008] In yet another embodiment, the spin electronic device comprises a multilayer structure having a negative spin polarization and a negative anisotropy field, the multilayer structure comprising a plurality of alternating first and second layers. Each of the first layers comprises FeCr x 、FeV x 、FeTi x 、FeCr x V y 、FeCr x Ti y 、FeV x Ti y and FeCr x V y Ti z At least one of , wherein each of x, y, and z is a positive number, and each of the second layers comprises Co. Each of the first layers has a first thickness between about 0.4 nm and about 0.8 nm, and each of the second layers has a second thickness between about 0.3 nm and about 0.6 nm. The spintronic device further includes one or more layers disposed above the multilayer structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Thus, a detailed understanding of the manner in which the above-recited features of the present disclosure are understood, a more particular description of the disclosure, the brief summary above, and the like, may be obtained by reference to the embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the drawings illustrate only typical embodiments of the disclosure and are therefore not to be considered limiting of its scope, as the disclosure may admit to other equally effective embodiments.

[0010] Figure 1 A magnetic recording apparatus embodying the present disclosure is shown.

[0011] Figure 2 is a fragmentary cross-sectional side view through the center of a read / write head facing a magnetic medium, according to one embodiment.

[0012] Figure 3ASchematic diagrams of multilayer structures with negative spin polarization and negative anisotropy field (-Hk) are shown according to various embodiments.

[0013] Figures 3B to 3C Shown are various embodiments utilizing Figure 3A Schematic diagram of a multilayer spintronic device.

[0014] Figure 3D Shown is the use of Figure 3A Schematic diagram of a multilayer magnetoresistive (MR) sensor.

[0015] Figure 3E Schematic diagrams illustrating certain embodiments of memory cell arrays in a cross-point configuration.

[0016] Figure 4 A graph is shown according to one embodiment, which shows Figure 3A Hk, saturation magnetic flux density (Bs) and effective magnetization intensity (M eff ).

[0017] Figure 5A A graph is shown according to one embodiment, which shows that when the thickness of the first sub-layer and the second sub-layer of the multilayer structure is changed in nanometers, the pinned layer (pinned layer) including CoFe and the Figure 3A Multi-layer structure Figure 3B Current-in-plane (CIP) giant magnetoresistance (GMR) in devices (%).

[0018] Figure 5B A graph is shown according to one embodiment, which shows that when Figure 3A The thicknesses of the first sublayer and the second sublayer of the multilayer structure are varied in nanometers while Hk is measured in T.

[0019] Figure 5C A graph is shown according to one embodiment, which shows that when Figure 3A The thickness of the first sublayer and the second sublayer of the multilayer structure is changed in nanometers when the unit T is M eff .

[0020] Figure 6A A graph is shown showing the effect of using a pinning layer including CoFe and a first sub-layer including FeCrx on the Cr content of the multi-layer structure when the atomic percentage (at%) of Cr is varied according to one embodiment. Figure 3A Multi-layer structure Figure 3BCIP-GMR ratio in % for the device.

[0021] Figure 6B A graph is shown according to one embodiment, which shows that when Figure 3A When the atomic percentage of Cr in the first sublayer of the multilayer structure containing FeCrx is changed, Hk in T, Bs in T and M in T are eff .

[0022] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one embodiment may be beneficially utilized on other embodiments without specific recitation. DETAILED DESCRIPTION

[0023] Hereinafter, reference is made to embodiments of the present disclosure. However, it should be understood that the present disclosure is not limited to the specifically described embodiments. On the contrary, any combination of the following features and elements (whether or not related to different embodiments) is considered to implement and practice the present disclosure. In addition, although the embodiments of the present disclosure can achieve advantages over other possible solutions and / or advantages over the prior art, whether a specific advantage is achieved by a given embodiment is not a limitation of the present disclosure. Therefore, the following aspects, features, embodiments and advantages are merely illustrative and are not considered to be elements or limitations of the appended claims unless expressly stated in the claims. Similarly, reference to "the present disclosure" should not be interpreted as a summary of any inventive subject matter disclosed herein and should not be considered to be elements or limitations of the appended claims unless expressly stated in the claims.

[0024] Aspects of the present disclosure are generally directed to a spintronic device for use in a magnetic media drive, a magnetoresistive random access memory device, a magnetic sensor, or a magnetic recording write head. The spintronic device includes a multilayer structure having a negative spin polarization and a negative anisotropy field. The multilayer structure includes a plurality of layers, each of the plurality of layers including a first sublayer comprising Fe and a second sublayer comprising Co. At least one of the first sublayer and the second sublayer comprises one or more of Cr, V, and Ti. The first sublayer and the second sublayer alternate. The negative anisotropy field of the multilayer structure is between about -0.5 T and about -0.8 T, and the effective magnetization of the multilayer structure is between about 2.4 T and about 2.8 T.

[0025] It should be understood that the embodiments discussed herein are applicable to data storage devices such as hard disk drives (HDDs) and tape drives such as tape embedded drives (TEDs) or pluggable tape media drives, such as products manufactured according to the Linear Tape Open (LTO) standard. An exemplary TED is described in co-pending patent application U.S. Publication No. 2020 / 0258544, entitled "Tape Embedded Drive," filed on March 26, 2019, which is assigned to the same assignee as the present application and is incorporated herein by reference. Therefore, unless expressly claimed, any reference to an HDD or tape drive in the detailed description is for illustrative purposes only and is not intended to limit the present disclosure. For example, references to magnetic disk media in HDD embodiments are provided by way of example only and may be substituted for magnetic tape media in tape drive embodiments. Furthermore, references to or claims involving magnetic recording devices or data storage devices are intended to include at least both HDDs and tape drives unless an HDD or tape drive device is expressly claimed.

[0026] It should also be understood that aspects disclosed herein, such as magnetoresistive devices, can be used in magnetic sensor applications other than HDDs and tape media drives, such as TEDs, such as spintronic devices other than HDDs and tape media drives. For example, aspects disclosed herein can be used in magnetoresistive random access memory (MRAM) devices (e.g., magnetic tunnel junctions as part of a memory element), magnetic sensors, or other magnetic elements in spintronic devices.

[0027] Figure 1 A magnetic recording apparatus 100 embodying the present disclosure is shown. As shown, at least one rotatable magnetic medium 112 is carried on a spindle 114 and is rotated by a disk drive motor 118. The magnetic recording on each disk is in the form of any suitable pattern of data tracks, such as an annular pattern of concentric data tracks (not shown) on the magnetic medium 112.

[0028] At least one slider 113 is positioned adjacent to the magnetic medium 112, with each slider 113 supporting one or more head assemblies 121. As the magnetic medium rotates, the slider 113 moves radially in and out over the media surface 122, allowing the head assemblies 121 to access different tracks of the magnetic medium 112 where desired data is written. Each slider 113 is attached to an actuator arm 119 via a suspension 115. The suspension 115 provides a slight spring force that biases the slider 113 toward the media surface 122. Each actuator arm 119 is attached to an actuator assembly 127. Figure 1The actuator member 127 shown may be a voice coil motor (VCM). The VCM comprises a coil that can move within a fixed magnetic field, with the direction and speed of the coil movement controlled by a motor current signal supplied by the control unit 129.

[0029] During operation of the magnetic recording device 100, the rotation of the magnetic medium 112 creates an air bearing between the slider 113 and the media surface 122, which exerts an upward force or lift on the slider 113. Thus, during normal operation, the air bearing counteracts the slight spring force of the suspension 115 and supports the slider 113 at a small, substantially constant distance off and slightly above the surface of the media 112. In the case of EAMR, the DC magnetic field generated from the auxiliary elements of the head assembly 121 enhances the writing capability, allowing the write elements of the head assembly 121 to effectively magnetize the data bits in the media 112.

[0030] The various components of the magnetic recording apparatus 100 are controlled in operation by control signals such as access control signals and internal clock signals generated by a control unit 129. Typically, the control unit 129 includes logic control circuitry, memory devices, and a microprocessor. The control unit 129 generates control signals that control various system operations, such as drive motor control signals on line 123 and head position and seek control signals on line 128. The control signals on line 128 provide the desired current profile to optimally move and position the slider 113 to the desired data track on the medium 112. Write and read signals are transmitted to and from the write and read heads on the assembly 121 via the recording channel 125.

[0031] The above description of a typical disk storage system and Figure 1 The accompanying description is for illustrative purposes only. It should be apparent that a disk storage system may include a large number of disks and actuators, and each actuator may support multiple sliders.

[0032] Figure 2 According to one embodiment of the present invention, Figure 1 The head assembly 200 is a schematic diagram of a cross-sectional side view of a rotatable magnetic disk 112 or other magnetic storage medium. The head assembly 200 may correspond to Figure 1 The head assembly 200 includes a media facing surface (MFS) 212, such as an air bearing surface (ABS) facing the rotatable magnetic disk 112. Figure 2 As shown, the rotatable magnetic disk 112 relatively moves in the direction indicated by arrow 232 , and the head assembly 200 relatively moves in the direction indicated by arrow 233 .

[0033] In one embodiment, which may be combined with other embodiments, the head assembly 200 includes a magnetic read head 211. The magnetic read head 211 may include a sensing element 204 disposed between shields S1 and S2. The sensing element 204 is a magnetoresistive (MR) sensing element, such as an element utilizing a tunneling magnetoresistive (TMR) effect, a geomagnetic magnetoresistive (GMR) effect, an abnormal magnetoresistive (EMR) effect, or a spin torque oscillator (STO) effect. The magnetic field of a magnetized region in the rotatable magnetic disk 112 (such as a perpendicularly recorded bit or a longitudinally recorded bit) may be detected by the sensing element 204 as a recorded bit.

[0034] The magnetic head assembly 200 includes a write head 210. In one embodiment that can be combined with other embodiments, the write head 210 includes a main pole 220, a front shield 206, a back shield (TS) 240, and a spintronic device 230 disposed between the main pole 220 and the TS 240. The main pole 220 serves as a first electrode. Each of the main pole 220, the spintronic device 230, the front shield 206, and the back shield (TS) 240 has a front portion at the MFS.

[0035] The main pole 220 includes a magnetic material such as CoFe, CoFeNi, FeNi, or other suitable magnetic materials. In one embodiment, which may be combined with other embodiments, the main pole 220 includes small grains of magnetic material with a random texture, such as a body-centered cubic (BCC) material formed with a random texture. For example, the random texture of the main pole 220 is formed by electrodeposition. The write head 210 includes a coil 218 surrounding the main pole 220, which energizes the main pole 220 to generate a write magnetic field to affect the magnetic recording medium of the rotatable disk 112. The coil 218 can be a spiral structure or a set of one or more flat structures.

[0036] In one embodiment, which may be combined with other embodiments, the main pole 220 includes a trailing cone 242 and a leading cone 244. The trailing cone 242 extends from a recessed position in the MFS 212 to the MFS 212. The leading cone 244 extends from a recessed position in the MFS 212 to the MFS 212. The trailing cone 242 and the leading cone 244 may have the same or different tapers relative to the longitudinal axis 260 of the main pole 220. In one embodiment, which may be combined with other embodiments, the main pole 220 does not include the trailing cone 242 and the leading cone 244. In such an embodiment, the main pole 220 includes a trailing side surface and a leading side surface, wherein the trailing side surface and the leading side surface are substantially parallel.

[0037] TS 240 includes a magnetic material such as FeNi or other suitable magnetic material and serves as a second electrode and a return pole for main pole 220. Front shield 206 may provide electromagnetic shielding and is separated from main pole 220 by a front gap 254.

[0038] In some embodiments, the spintronic device 230 is positioned close to the main pole 220 and reduces the coercivity of the magnetic recording medium, allowing a smaller write field to be used to record data. In such embodiments, an electron current is applied from a current source 270 to the spintronic device 230 to generate a microwave field. The electron current can include a direct current (DC) waveform, a pulsed DC waveform, and / or a pulsed current waveform that shifts to positive and negative voltages, or other suitable waveforms. In other embodiments, the electron current is applied from the current source 270 to the spintronic device 230 to generate a high-frequency alternating current (AC) field in the medium.

[0039] In one embodiment, which may be combined with other embodiments, the spin electronic device 230 is electrically coupled to the main pole 220 and the TS 240. The main pole 220 and the TS 240 are separated in a region by an insulating layer 272. A current source 270 can provide an electron current to the spin electronic device 230 through the main pole 220 and the TS 240. For direct current or pulsed current, the current source 270 can cause the electron current to flow from the main pole 220 through the spin electronic device 230 to the TS 240, or can cause the electron current to flow from the TS 240 through the spin electronic device 230 to the main pole 220, depending on the orientation of the spin electronic device 230. In one embodiment, which may be combined with other embodiments, the spin electronic device 230 is coupled to an electrical lead that provides a current other than that from the main pole 220 and / or the TS 240.

[0040] Figure 3A A schematic diagram of a multilayer structure 300 having negative spin polarization and a negative anisotropy field (-Hk) according to one embodiment is shown. For example, the multilayer structure 300 can be used as a free layer in a magnetic tunnel junction (MTJ) device (e.g., a spin-orbit torque (SOT) MTJ device), as a free layer in a spin-orbit torque device in an energy-assisted magnetic recording (EAMR) write head, as a free layer in a magnetoresistive random access memory (MRAM) device, as a field generating layer (FGL) in a microwave-assisted magnetic recording (MAMR) write head, as a pinned layer in a magnetoresistive (MR) device, or used in other spintronic devices.

[0041] As used herein, the multilayer structure 300 can be implemented in a magnetic recording head, including a magnetic recording write head (e.g., as an FGL in a MAMR application) and a magnetic recording read head (e.g., as a free layer in a sensor within a read head). In addition, the multilayer structure 300 can be implemented in a magnetic sensor, such as a read sensor, or any other non-HDD sensing application.

[0042] The multilayer structure 300 includes a plurality of layers 302a to 302n. Each layer 302a to 302n includes a first sublayer 304 and a second sublayer 306 disposed above the first sublayer 304, such that the first sublayers 304 and the second sublayers 306 alternate throughout the multilayer structure 300. The first sublayer 304 includes iron (Fe), the second sublayer 306 includes cobalt (Co), and the first sublayer 304 and / or the second sublayer 306 additionally include at least one of chromium (Cr), vanadium (V), or titanium (Ti).

[0043] For example, in one embodiment, the second sub-layer 306 includes Co and the first sub-layer 304 includes FeCr x 、FeV x or FeTi x , where the x value in each is a positive number and can be a non-integer value or an integer value. For example, the first sublayer 304 may include FeCr 28 、FeCr 20 、FeCr 40 、FeCr 16 、FeCr 46 、FeTi5、FeTi 11 、FeTi 23 、FeV 10 、FeV 20 or FeV 30 In some embodiments where the second sub-layer 306 includes Co, the first sub-layer 304 includes FeCr x V y 、FeCr x Ti y 、FeV x Ti y or FeCr x V y Ti z , wherein the value of x, y and / or z in each is a positive number and can be a non-integer value or an integer value. In some embodiments, the value of each of x, y and / or z is between 1 and 46.

[0044] In another embodiment, the first sub-layer 304 comprises Fe and the second sub-layer 306 comprises CoCr x , CoV x or CoTi x , wherein the value of x in each is a positive number and can be a non-integer value or an integer value. In some embodiments where the first sublayer 304 comprises Fe, the second sublayer 306 comprises CoCr x V y 、CoCr x Ti y , CoV xTi y or CoCr x V y Ti z , wherein the value of x, y and / or z in each is a positive number and can be a non-integer value or an integer value. In some embodiments, the value of each of x, y and / or z is between 1 and 46.

[0045] In yet another embodiment, both the first sub-layer 304 and the second sub-layer 306 include one or more of Cr, V, and Ti. For example, the first sub-layer 304 includes FeCr x 、FeV x 、FeTi x 、FeCr x V y 、FeCr x Ti y 、FeV x Ti y and FeCr x V y Ti z In some embodiments, the value of each of x, y, and / or z is between 1 and 46. The second sublayer 306 includes CoCr x , CoV x 、CoTi x 、CoCr x V y 、CoCr x Ti y , CoV x Ti y and CoCr x V y Ti z In one of, wherein each of x, y and / or z in each of the values ​​is a positive number, and can be a non-integer value or an integer value. In some embodiments, the value of each of x, y and / or z is between 1 and 46.

[0046] Each layer 302a to 302n may collectively include Co a / Fe b (Cr x V y Ti z), where a, b, x, y, and z are atomic percentages. One or more of x, y, and z can be 0 at%, as long as at least one of x, y, and z is a positive number greater than 0 at%. The atomic percentage of each of Co, Fe, Cr, V, and Ti is selected based on the total number of electrons. For example, the first sublayer 304 including Fe and the second sublayer 306 including Co have a total electron / atom of approximately 26.5. As shown by the Slator Pauling plot, when the total number of electrons in each layer 302a to 320n is reduced by adding one or more of Cr, V, and Ti, the saturation magnetic flux density (Bs) of the layers 302a to 302n is reduced.

[0047] The following formula 1 can be used to determine the Co based on the total number of electrons a / Fe b (Cr x V y Ti z ) in the quantities a, b, x, y, and z:

[0048] Formula 1

[0049]

[0050] Therefore, the doping amount of each of Cr, V, and Ti depends on the total number of electrons in each layer 302a to 320n. In some embodiments, the total number of electrons per atom is greater than 24, as shown in Equation 1.

[0051] Each first sub-layer 304 has a first thickness 314 in the y-direction, and each second sub-layer 306 has a second thickness 316 in the y-direction. Figures 4 to 5C As further discussed in

[0045] , first thickness 314 and second thickness 316 can be the same, or first thickness 314 and second thickness 316 can be different. In some embodiments, first thickness 314 is greater than or equal to second thickness 316. First thickness 314 can be between about 0.3 nm and about 0.8 nm. Second thickness 316 can be between about 0.3 nm and about 0.6 nm.

[0052] The multilayer structure 300 may include any number of layers 302a to 302n until a desired total thickness 310 is reached. The total thickness 310 of the material may be from about 1 nm to about 20 nm, such as from about 5 nm to about 8 nm. In some embodiments, an additional first sublayer 304a is optionally included as a capping layer for the multilayer structure 300. In such embodiments, the additional first sublayer 304a is in contact with the next layer of the spin electronic device, such as a capping layer or a spacer layer. The additional first sublayer 304a has a first thickness 314. The additional first sublayer 304a may be used in certain spin electronic devices to control both interface and bulk effects. For example, FeCr has a stronger negative interface spin polarization than Co, and therefore an additional FeCr layer may be included as the first additional sublayer 304a adjacent to the spacer layer or other subsequent layer. Therefore, the first additional sublayer 304a may include FeCr x 、FeV x 、FeTi x 、FeCr x V y 、FeCr x Ti y 、FeV x Ti y or FeCr x V y Ti z , wherein the value of x is a positive number and can be a non-integer value or an integer value. Although the second sublayer 306 is shown as being disposed on the first sublayer 304, in some embodiments, the first sublayer 304 is disposed on the second sublayer 306. In such embodiments, the additional first sublayer 304a may not be included.

[0053] Figure 3B Shown is the use of Figure 3A Schematic MFS view of a spin electronic device 350 having a multilayer structure 300. The spin electronic device 350 can be used as Figure 2 The spintronic device 230 or sensing element 204 is shown. For example, the spintronic device 350 can be a SOT MTJ device or a spin-orbit torque device. The spintronic device 350 can be used in a magnetic media drive, a magnetoresistive random access memory device, a magnetic sensor, or a magnetic recording write head. The spintronic device 350 is only one example or embodiment of a spintronic device that can utilize the multilayer structure 300 and is not intended to be limiting.

[0054] like Figure 3BAs shown, the multilayer structure 300 is disposed above the seed layer 320, the spacer layer 322 is disposed above the multilayer structure 300, the pinning layer 324 is disposed above the spacer layer 322, and the capping layer 326 is disposed above the pinning layer 324. The seed layer 320 may include a NiFeTa / Ru / Cr multilayer structure. In some embodiments, the seed layer 320 is disposed above or in contact with a main electrode (not shown), such as Figure 2 The main electrode 220 is provided in FIG. The spacer layer 322 may comprise a Cu, NiAl, or Ag-based material. A thin layer of Cr or V may optionally be inserted between the multilayer structure 300 and the spacer layer 322 to enhance the negative interface scattering effect. The pinning layer 324 may comprise CoFe. The capping layer 326 may comprise a Cr / Cu / Ru multilayer structure. As used in the spintronic device 350, the multilayer structure 300 may comprise, for example, five to ten layers 302a to 302n. The multilayer structure 300 may be a free layer.

[0055] Figure 3C According to another embodiment, the use of Figure 3A Schematic MFS view of a spin electronic device 360 ​​having a multilayer structure 300. The spin electronic device 360 ​​can be used as Figure 2 The spintronic device 230 or sensing element 204 of the read head 211 is shown. The spintronic device 360 ​​can be used in applications such as Figure 2 Magnetic sensors outside the context of a read head or for a magnetic recording write head to provide an AC field (e.g., as part of a spin torque oscillator (STO) for MAMR). Figure 3C As shown, a seed layer 320 is disposed above the main pole 362, a multilayer structure 300 is disposed above the seed layer 320, a spacer layer 322 is disposed above the multilayer structure 300, a magnetic layer 366 such as a spin polarization layer (SPL) or a spin torque layer (STL) is disposed above the spacer layer 322, and a trailing shield 364 is disposed above the magnetic layer 366.

[0056] The multilayer structure 300 may be a FGL. The main pole 362 includes a magnetic material such as CoFe, CoFeNi or FeNi, or other suitable magnetic materials. The seed layer 320 may include a NiFeTa / Ru / Cr multilayer structure. The spacer layer 322 may include a Cu, NiAl or Ag-based material. A thin layer of Cr or V may be optionally inserted between the multilayer structure 300 and the spacer layer 322 to enhance the negative interface scattering effect. The magnetic layer 366 may include NiFe, CoMnGe or CoFe. The tail shield 364 includes a magnetic material such as CoFe, FeNi or other suitable magnetic material, and serves as a second electrode and a return pole for the main pole 362. The main pole 362 may be Figure 2 The main pole 220, and the tail shield can be Figure 2TS 240. As used in the spintronic device 360, the multilayer structure 300 can include, for example, five to ten layers 302a to 302n, resulting in a total thickness of the multilayer structure 300 between about 4 nm and about 15 nm.

[0057] Figure 3D Shown is the use of Figure 3A Schematic MFS view of a spintronic device or MR sensor 370 having a multilayer structure 300. The spintronic device or MR sensor 370 can be used as Figure 2 The sensing element 204 of the read head 211 or the spintronic device 230 is shown. The MR sensor 370 can be used in an MR device, a magnetic recording read head, or in a magnetic recording apparatus such as Figure 2 For example, the spintronic device or MR sensor 370 can be used in a tunneling magnetoresistive (TMR) device, a giant magnetoresistive (GMR) device, a current-in-plane (CIP) GMR device, or a current-perpendicular-to-the-plane (CPP) GMR device. Figure 3D The MR sensor 370 is interchangeably referred to as a spintronic device 370 throughout.

[0058] like Figure 3D As shown, a spacer layer 372 is disposed on the multilayer structure 300, a first pinned layer 374 is disposed on the spacer layer 372, a barrier layer 376 is disposed on the first pinned layer 374, and a free layer 378 is disposed on the barrier layer 376. In a spintronic device or MR sensor 370, the multilayer structure 300 may be a second pinned layer, wherein the magnetizations of the first pinned layer 374 and the multilayer structure 300 are antiparallel to each other. In an MR device, the multilayer structure 300 may be disposed above a first shield (not shown), and a second shield (not shown) may be disposed above the free layer 378. In addition, one or more layers may be disposed between the multilayer structure 300 and the first shield, such as a seed layer and / or a spacer layer, and one or more layers may be disposed between the free layer 378 and the second shield, such as a capping layer.

[0059] The first pinned layer 374 is magnetic and is formed of a material including one or more of Co, Fe, B, Ni, and / or alloys thereof, such as CoFe or NiFe. The first pinned layer 374 may have a positive spin polarization, while the multilayer structure 300 has a negative spin polarization. The spacer layer 372 is non-magnetic and is formed of a metallic material, such as Ru. The spacer layer 372 promotes that the magnetizations of the first pinned layer 374 and the multilayer structure 300 are antiparallel to each other. The barrier layer 376 is non-magnetic and includes MgO, aluminum oxide (Al2O3), and amorphous metal. x O x) such as Al 2 O 3 or any other suitable insulating material. The free layer 378 is formed of a material including one or more of Ni, Fe, Co, B and / or Hf.

[0060] Figure 3E is a schematic diagram of certain embodiments of a memory cell array 390 in a cross-point configuration. The memory cell array 390 includes a plurality of memory cells 392 formed from spintronic devices such as SOT-based MRAM devices. In some embodiments, each memory cell 392 of the memory cell array 390 includes Figure 3B The spin electronic device 350 includes the multilayer structure 300. In other embodiments, the memory cell 392 of the memory cell array 390 may include a Figure 3A Other types of spintronic devices, such as the multilayer structure 300 Figure 3C 360 of spintronic devices.

[0061] Each of the memory cells 392 can be in a state representing a 1 or 0 bit value. The memory cell array 390 includes a plurality of bottom electrodes 394 and a plurality of spin Hall electrodes or spin track material electrodes 396. The spin track material electrodes 396 include Figure 3A The multilayer structure 300 is shown. Each memory cell 392 can be part of a two-terminal device or a three-terminal device. For example, in a two-terminal device, the bottom electrode 394 can serve as a bit line, and the spin-track material electrode 396 can serve as a word line. For example, in a three-terminal device, the bottom electrode 394 can serve as a bit line and a read word line, and the spin-track material electrode 396 can serve as a write word line.

[0062] like Figure 3E The cross-point array embodiment shown is merely an exemplary MRAM embodiment, and the various spintronic device embodiments disclosed herein can be implemented in other types of MRAM devices. Therefore, the memory cell array 390 is not intended to be limiting. Other architectures of the memory cell array 390 may include various types and combinations of terminals, gates, transistors, and wiring.

[0063] Figure 4 A graph 400 is shown showing the thickness 314 of the first sub-layer 304 and the thickness 316 of the second sub-layer 306 as they vary in nanometers, according to one embodiment. Figure 3A The Hk in Tesla (T), the saturation magnetic flux density (Bs) in T, and the effective magnetization (M) in T of the multilayer structure 300 are shown in FIG. eff ). The multilayer structure 300 may be used in a spintronic device, such as Figure 3B Spintronic devices 350, Figure 3CSpintronic Devices 360, or Figure 3D MR sensor 370.

[0064] In graph 400, the first sub-layer 304 comprises FeCr 28 , and the second sub-layer 306 includes Co. Although in the embodiment shown in graph 400, the first sub-layer 304 includes FeCr 28 , but the first sub-layer 304 may alternatively comprise FeV x 、FeTi x 、FeCr x V y 、FeCr x Ti y 、FeV x Ti y 、FeCr x V y Ti z or other FeCr mentioned above x materials, and the first sub-layer 304 is not intended to be limited to FeCr 28 In addition, the second sub-layer 306 may also include one or more of Cr, V, or Ti, as described above. When the first sub-layer 304 includes Fe and the second sub-layer 306 includes CoCr x , CoV x 、CoTi x 、CoCr x V y 、CoCr x Ti y , CoV x Ti y and CoCr x V y Ti z Similar results are expected when one of the following is used: wherein the values ​​of each of x, y, and / or z in each are positive and can be non-integer or integer values. Therefore, the graph 400 is not intended to be limited to FeCr 28 as the material of the first sub-layer 304 and Co as the material of the second sub-layer 306 .

[0065] The thickness 314 of the first sublayer 304 is shown at the bottom of the graph along the x-axis, while the thickness 316 of the second sublayer 306 is shown at the top of the graph 400 along the x-axis. The graph 400 is broken down into several sections 402 to 410. In each of the sections 402 to 410, the thickness of the first sublayer 304 varies between approximately 0.2 nm and approximately 0.8 nm. In the first section 402, the second sublayer 306 has a thickness of approximately 0.2 nm. In the second section 404, the second sublayer 306 has a thickness of approximately 0.3 nm. In the third section 406, the second sublayer 306 has a thickness of approximately 0.4 nm. In the fourth section 408, the second sublayer 306 has a thickness of approximately 0.45 nm. In the fifth section 410, the second sublayer 306 has a thickness of approximately 0.5 nm.

[0066] Graph 400 shows that a negative Hk of approximately −0.6 T is achieved when the first sublayer 304 has a thickness 314 between approximately 0.3 nm and approximately 0.8 nm and the second sublayer 306 has a thickness 316 between approximately 0.3 nm and approximately 0.6 nm. Graph 400 also shows that a greater M is achieved when the first sublayer 304 has a thickness 314 between approximately 0.3 nm and approximately 0.5 nm and the second sublayer 306 has a thickness 316 between approximately 0.35 nm and approximately 0.5 nm. eff and Bs.

[0067] Figure 5A A graph 500 is shown showing the effect of using a pinning layer 324 including CoFe and a second sub-layer 306 as the thickness 314 of the first sub-layer 304 and the thickness 316 of the second sub-layer 306 of the multi-layer structure 300 are varied in nanometers, according to one embodiment. Figure 3A The multi-layer structure of 300 Figure 3B The multilayer structure 300 can be used in spintronic devices such as Figure 3B Spintronic devices 350, Figure 3C Spintronic Devices 360, or Figure 3D MR sensor 370.

[0068] In graph 500, the first sub-layer 304 comprises FeCr 28 , and the second sub-layer 306 includes Co. Although in the embodiment shown in graph 500, the first sub-layer 304 includes FeCr 28 , but the first sub-layer 304 may alternatively comprise FeV x 、FeTi x 、FeCr x V y 、FeCr x Ti y、FeV x Ti y 、FeCr x V y Ti z or other FeCr mentioned above x materials, and the first sub-layer 304 is not intended to be limited to FeCr 28 In addition, the second sub-layer 306 may also include one or more of Cr, V, or Ti, as described above. When the first sub-layer 304 includes Fe and the second sub-layer 306 includes CoCr x , CoV x 、CoTi x 、CoCr x V y 、CoCr x Ti y , CoV x Ti y and CoCr x V y Ti z Similar results are expected when one of the following is used: wherein the values ​​of each of x, y, and / or z in each are positive and can be non-integer or integer values. Therefore, the graph 500 is not intended to be limited to FeCr 28 as the material of the first sub-layer 304 and Co as the material of the second sub-layer 306 .

[0069] The thickness 314 of the first sublayer 304 is shown on the y-axis, the thickness 316 of the second sublayer 306 is shown on the x-axis, and the negative CIP-GMR achieved is indicated by key 502. Negative CIP-GMR indicates that the multilayer 300 has a negative spin polarization because the pinned layer including CoFe has a positive spin polarization. As shown by arrow 504, the first sublayer 304 having a larger thickness 314 of about 0.3 nm to about 0.8 nm and the second sublayer 306 having a thickness between about 0.35 nm and about 0.5 nm result in a higher negative spin polarization.

[0070] Figure 5B A graph 550 is shown according to one embodiment, which shows that when Figure 3A The multilayer structure 300 may be used in a spin electronic device, such as Figure 3B Spintronic devices 350, Figure 3C Spintronic Devices 360, or Figure 3D MR sensor 370.

[0071] In graph 550, the first sub-layer 304 comprises FeCr28 , and the second sub-layer 306 includes Co. Although in the embodiment shown in graph 550, the first sub-layer 304 includes FeCr 28 , but the first sub-layer 304 may alternatively comprise FeV x 、FeTi x 、FeCr x V y 、FeCr x Ti y 、FeV x Ti y 、FeCr x V y Ti z or other FeCr mentioned above x materials, and similar results will be obtained. In addition, the second sub-layer 306 may also contain one or more of Cr, V or Ti, as described above. When the first sub-layer 304 contains Fe and the second sub-layer 306 includes CoCr x , CoV x 、CoTi x 、CoCr x V y 、CoCr x Ti y , CoV x Ti y and CoCr x V y Ti z Similar results are expected when one of , wherein each of the values ​​of x, y, and / or z in each is positive and can be non-integer or integer values. Therefore, the graph 550 is not intended to be limited to FeCr 28 as the material of the first sub-layer 304 and Co as the material of the second sub-layer 306 .

[0072] The thickness 314 of the first sub-layer 304 is shown on the y-axis, the thickness 316 of the second sub-layer 306 is shown on the x-axis, and the achieved Hk is indicated by key 552. Line 554 shows the approximate boundary of the thickness 314 of the first sub-layer 304 and the thickness 316 of the second sub-layer 306 that achieve the highest negative Hk. As shown by line 554, the first sub-layer 304 having a thickness 314 between about 0.3 nm and about 0.8 nm and the second sub-layer 306 having a thickness 316 between about 0.3 nm and about 0.6 nm result in an Hk of about -0.6T to about -0.7T.

[0073] Line 556 shows or covers the use of Figure 5AThe data of the graph 500 realizes the approximate boundaries of the thicknesses 314, 316 of the first sublayer 304 and the second sublayer 306 for the highest negative Hk and the highest negative spin polarization. As shown by line 556, the first sublayer 304 having a thickness 314 between about 0.5 nm and about 0.7 nm and the second sublayer 306 having a thickness 316 between about 0.35 nm and about 0.5 nm together result in the highest negative Hk and the highest negative spin polarization.

[0074] Figure 5C A graph 590 is shown according to one embodiment, which shows that when Figure 3A The thickness 314 of the first sublayer 304 and the thickness 316 of the second sublayer 306 of the multilayer structure 300 are changed in nanometers when the unit T is M eff The multilayer structure 300 may be used in a spintronic device such as Figure 3B Spintronic devices 350, Figure 3C Spintronic Devices 360, or Figure 3D MR sensor 370.

[0075] In graph 550, the first sub-layer 304 comprises FeCr 28 , and the second sub-layer 306 includes Co. Although in the embodiment shown in graph 550, the first sub-layer 304 includes FeCr 28 , but the first sub-layer 304 may alternatively comprise FeV x 、FeTi x 、FeCr x V y 、FeCr x Ti y 、FeV x Ti y 、FeCr x V y Ti z or other FeCr mentioned above x materials, and similar results will be obtained. In addition, the second sub-layer 306 may also contain one or more of Cr, V or Ti, as described above. When the first sub-layer 304 contains Fe and the second sub-layer 306 includes CoCr x , CoV x 、CoTi x 、CoCr x V y 、CoCr x Ti y , CoV x Ti y and CoCr x V y Ti zSimilar results are expected when one of the graphs 590 and 591 is used, wherein each of the values ​​of x, y, and / or z in each of the graphs 590 is positive and may be non-integer or integer values. 28 as the material of the first sub-layer 304 and Co as the material of the second sub-layer 306 .

[0076] The thickness 314 of the first sub-layer 304 is shown on the y-axis, the thickness 316 of the second sub-layer 306 is shown on the x-axis, and the achieved M eff Indicated by key 592. Line 594 shows or encompasses the time it takes to achieve the highest M eff The approximate boundary of the thickness 314 of the first sub-layer 304 and the thickness 316 of the second sub-layer 306 is shown as line 594. As shown by line 594, the first sub-layer 304 having a thickness 314 between about 0.3 nm and about 0.8 nm and the second sub-layer 306 having a thickness 316 between about 0.3 nm and about 0.6 nm results in an M of about 2.2T to about 2.6T. eff .

[0077] Line 596 illustrates or encompasses the use of Figure 5A The graph of 500 data to achieve the highest M eff and the approximate boundary of the thicknesses 314, 316 of the first and second sublayers 304, 306 of the highest negative spin polarization. As shown by line 596, the first sublayer 304 having a thickness 314 between about 0.4 nm and about 0.6 nm and the second sublayer 306 having a thickness 316 between about 0.35 nm and about 0.5 nm together result in the highest M eff and highest negative spin polarization.

[0078] Therefore, considering Figures 5A to 5C For each of the graphs 500, 550, 590, the thickness 314 of the first sub-layer 304 and the thickness 316 of the second sub-layer 306 may be selected based on the desired overall properties of the multi-layer structure 300 within the device. For example, if a higher M eff , the first sublayer 304 may have a thickness of about 0.4 nm to about 0.6 nm, while if a higher negative Hk is desired, the first sublayer 304 may have a thickness of about 0.5 nm to about 0.7 nm. Thus, the multilayer structure of the multilayer structure 300 may be customized or modified as needed to produce desired properties.

[0079] Figure 6A A graph 600 is shown according to one embodiment, which shows that when the multilayer structure 300 includes FeCr x When the atomic percentage (at%) of Cr in the first sub-layer 304 is changed, the pinning layer 324 including CoFe and Figure 3AThe multi-layer structure of 300 Figure 3B The CIP-GMR ratio in the device 350 is expressed in %. The multilayer structure 300 can be used in a spintronic device such as Figure 3B Spintronic devices 350, Figure 3C Spintronic Devices 360, or Figure 3D MR sensor 370.

[0080] Although in the embodiment shown in graph 600, the first sub-layer 304 comprises FeCr x , but the first sub-layer 304 may alternatively comprise FeV x 、FeTi x 、FeCr x V y 、FeCr x Ti y 、FeV x Ti y or FeCr x V y Ti z In this case, the atomic percentages of Cr, V, and / or Ti will vary in a similar manner to achieve similar results. In addition, the second sublayer 306 may also contain one or more of Cr, V, or Ti, as described above. When the first sublayer 304 contains Fe and the second sublayer 306 includes CoCr x , CoV x 、CoTi x 、CoCr x V y 、CoCr x Ti y , CoV x Ti y and CoCr x V y Ti z Similar results are expected when one of the following is used: wherein each of the values ​​of x, y, and / or z in each is positive and can be non-integer or integer values. Therefore, the graph 600 is not intended to be limited to FeCr x as the material of the first sub-layer 304 and Co as the material of the second sub-layer 306 .

[0081] As shown in graph 600, when the first sub-layer 304 has a thickness of about 0.4 nm, Cr between about 20 atomic percent and about 40 atomic percent results in a maximum negative CIP-GMR of about -0.025% to about -0.05%. 28 ) results in a negative CIP-GMR of about -0.04% to about -0.05%.

[0082] Figure 6B A graph 650 is shown according to one embodiment showing that when FeCr x When the atomic percentage (at%) of Cr in the first sub-layer 304 changes, Figure 3A Hk in T, Bs in T, and M in T of the multilayer structure 300 eff The multilayer structure 300 may be used in a spintronic device such as Figure 3B Spintronic devices 350, Figure 3C Spintronic Devices 360, or Figure 3D MR sensor 370.

[0083] Although in the embodiment shown in graph 650, the first sub-layer 304 comprises FeCr x , but the first sub-layer 304 may alternatively comprise FeV x 、FeTi x 、FeCr x V y 、FeCr x Ti y 、FeV x Ti y or FeCr x V y Ti z In this case, the atomic percentages of Cr, V, and / or Ti will vary in a similar manner to achieve similar results. In addition, the second sublayer 306 may also contain one or more of Cr, V, or Ti, as described above. When the first sublayer 304 contains Fe and the second sublayer 306 includes CoCr x , CoV x 、CoTi x 、CoCr x V y 、CoCr x Ti y , CoV x Ti y and CoCr x V y Ti z Similar results are expected when one of the following is used: wherein each of the values ​​of x, y, and / or z in each is positive and can be non-integer or integer values. Therefore, the graph 650 is not intended to be limited to FeCr x as the material of the first sub-layer 304 and Co as the material of the second sub-layer 306 .

[0084] As shown in graph 650, the atomic percentage is between about 20% (ie, FeCr 20) results in an M of about 2.5T to about 2.7T. eff and Hk of about -0.7T. Therefore, considering Figures 6A to 6B For each of the graphs 600, 650, the FeCr content of the first sub-layer 304 may be selected based on the desired overall properties of the multi-layer structure 300 within the device. x For example, if a higher M eff or a higher negative Hk, the first sub-layer 304 may include FeCr 20 , whereas if a higher negative spin polarization is desired, the first sublayer 304 may contain FeCr 28 Thus, the multi-layer structure of multi-layer structure 300 may be customized or modified as needed to produce desired properties.

[0085] Thus, utilizing a multilayer structure comprising alternating layers of Co and Fe, wherein at least one of the Co or Fe layers comprises one or more of Cr, V, and Ti, both negative spin polarization and a negative anisotropy field can be achieved. Furthermore, various parameters of the multilayer structure can be modified as needed to produce the desired characteristics of the multilayer structure, such as varying the thickness of the Co and Fe sublayers or varying the composition of Cr, V, and / or Ti used. Consequently, spintronic devices, such as those included within MAMR, CPP-GMR, and MRAM devices, have greater degrees of freedom, resulting in more efficient and improved devices.

[0086] In one embodiment, a spintronic device includes a multilayer structure having a negative spin polarization and a negative anisotropy field, the multilayer structure including a plurality of layers, each of the plurality of layers including a first sublayer including Fe and a second sublayer including Co, wherein at least one of the first sublayer and the second sublayer further includes one or more of Cr, V, and Ti. The first sublayers and the second sublayers alternate.

[0087] The first sublayer contains FeCr x 、FeV x 、FeTi x 、FeCr x V y 、FeCr x Ti y 、FeV x Ti y or FeCr x V y Ti z The value of each of x, y and z is a positive number. The second sublayer includes CoCr x , CoV x 、CoTi x 、CoCr x V y 、CoCrx Ti y , CoV x Ti y or CoCr x V y Ti z One of x, y, and z. Each of the values ​​of x, y, and z is a positive number. Each of the first sublayers has a first thickness between approximately 0.4 nm and approximately 0.8 nm. Each of the second sublayers has a second thickness between approximately 0.3 nm and approximately 0.6 nm. The multilayer structure is a free layer, a pinned layer, or a field generating layer. The magnetic media drive includes a spintronic device. The magnetoresistive random access memory device includes a spintronic device. The magnetic sensor includes a spintronic device. The magnetic recording head includes a spintronic device.

[0088] In another embodiment, a spin electronic device includes a substrate and a multilayer structure having a negative spin polarization and a negative anisotropy field disposed over the substrate, the multilayer structure including a plurality of alternating first and second layers. Each of the first layers includes Fe and one or more of Cr, V, and Ti, and each of the second layers includes Co. Each of the first layers has a first thickness that is greater than or equal to a second thickness of each of the second layers. The spin electronic device further includes a capping layer disposed over the multilayer structure.

[0089] The multilayer structure is a free layer, a pinned layer, or a field generating layer. Each of the first layers has a first thickness between about 0.4 nm and about 0.8 nm, and each of the second layers has a second thickness between about 0.3 nm and about 0.6 nm. The first layers each contain FeCr x 、FeV x 、FeTi x 、FeCr x V y 、FeCr x Ti y 、FeV x Ti y or FeCr x V y Ti z Each of x, y, and z is a number between 1 and 46. The second layer each includes CoCr x , CoV x 、CoTi x 、CoCr x V y 、CoCr x Ti y , CoV x Ti y or CoCrx V y Ti z Each of x, y and z is a number between 1 and 46. The covering layer is a first thickness containing FeCr x 、FeV x 、FeTix、FeCr x V y 、FeCr x Ti y 、FeV x Ti y or FeCr x V y Ti z The invention also provides an additional first layer of a magnetic medium drive including a spintronic device. The magnetoresistive random access memory device includes a spintronic device. The magnetic sensor includes a spintronic device. The magnetic recording head includes a spintronic device.

[0090] In yet another embodiment, the spin electronic device comprises a multilayer structure having a negative spin polarization and a negative anisotropy field, the multilayer structure comprising a plurality of alternating first and second layers. Each of the first layers comprises FeCr x 、FeV x 、FeTi x 、FeCr x V y 、FeCr x Ti y 、FeV x Ti y and FeCr x V y Ti z At least one of , wherein each of x, y, and z is a positive number, and each of the second layers comprises Co. Each of the first layers has a first thickness between about 0.4 nm and about 0.8 nm, and each of the second layers has a second thickness between about 0.3 nm and about 0.6 nm. The spintronic device further includes one or more layers disposed above the multilayer structure.

[0091] The one or more layers include a cover layer disposed in contact with the multilayer structure, the cover layer being a first thickness containing FeCr x 、FeV x 、FeTi x 、FeCr x V y 、FeCr x Ti y 、FeV x Ti y or FeCr xV y Ti z The multilayer structure is a free layer, a pinned layer, or a field generating layer. The negative anisotropy field of the multilayer structure is between about -0.5 T and about -0.8 T, and the effective magnetization of the multilayer structure is between about 2.4 T and about 2.8 T. Each of the second layers further comprises one or more of Cr, V, and Ti. The magnetic media drive includes a spintronic device. The magnetoresistive random access memory device includes a spintronic device. The magnetic sensor includes a spintronic device. The magnetic recording head includes a spintronic device.

[0092] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be envisaged without departing from the basic scope thereof, and the scope of the disclosure is determined by the claims that follow.

Claims

1. A spintronic device comprising: A multilayer structure having a negative spin polarization and a negative anisotropy field, the multilayer structure comprising a plurality of layers, each of the plurality of layers comprising a first sublayer comprising Fe and a second sublayer comprising Co, wherein at least one of the first sublayer and the second sublayer further comprises one or more of Cr, V, and Ti, and wherein the first sublayer and the second sublayer alternate and contact each other.

2. The spintronic device of claim 1 , wherein the first sublayer comprises FeCr x 、FeV x 、FeTi x 、FeCr x V y 、FeCr x Ti y 、FeV x Ti y or FeCr x V y Ti z One of , and wherein the value of each of x, y, and z is a positive number.

3. The spintronic device of claim 1 , wherein the second sublayer comprises CoCr x , CoV x 、CoTi x 、CoCr x V y 、CoCr x Ti y , CoV x Ti y or CoCr x V y Ti z One of , and wherein the value of each of x, y, and z is a positive number.

4. The spin electronic device of claim 1 , wherein each of the first sublayers has a first thickness between 0.4 nm and 0.8 nm, and wherein each of the second sublayers has a second thickness between 0.3 nm and 0.6 nm. The spintronic device according to claim 1 , wherein the multilayer structure is a free layer, a pinned layer, or a field generating layer. 6 . A magnetic media drive comprising the spintronic device according to claim 1 . 7 . A magnetoresistive random access memory device comprising the spintronic device according to claim 1 . 8 . A magnetic sensor comprising the spintronic device according to claim 1 . 9 . A magnetic recording head comprising the spintronic device according to claim 1 .

10. A spin electronic device comprising: substrate; a multilayer structure having a negative spin polarization and a negative anisotropy field disposed over the substrate, the multilayer structure comprising a plurality of alternating first and second layers in contact with each other, wherein each of the first layers comprises Fe and one or more of Cr, V, and Ti, and each of the second layers comprises Co, wherein each of the first layers has a first thickness greater than or equal to a second thickness of each of the second layers; and A cover layer is disposed over the multi-layer structure.

11. The spin electronic device according to claim 10, wherein the multilayer structure is a free layer, a pinned layer, or a field generating layer, and wherein each of the first layers has a first thickness between 0.4 nm and 0.8 nm, and each of the second layers has a second thickness between 0.3 nm and 0.6 nm.

12. The spin electronic device according to claim 10, wherein the first layers each comprise FeCr x 、FeV x 、FeTi x 、FeCr x V y 、FeCr x Ti y 、FeV x Ti y or FeCr x V y Ti z One of , where each of x, y, and z is a number between 1 and 46.

13. The spin electronic device of claim 10, wherein the second layers each comprise CoCr x , CoV x 、CoTi x 、CoCr x V y 、CoCr x Ti y , CoV x Ti y or CoCr x V y Ti z One of , where each of x, y, and z is a number between 1 and 46.

14. The spintronic device according to claim 10, wherein the capping layer is a FeCr-containing x 、FeV x 、FeTi x 、FeCr x V y 、FeCr x Ti y 、FeV x Ti y or FeCr x V y Ti z Additional first floor.

15. A magnetic media drive comprising the spintronic device according to claim 10. 16 . A magnetoresistive random access memory device comprising the spintronic device according to claim 10 . 17 . A magnetic sensor comprising the spintronic device according to claim 10 .

18. A magnetic recording head comprising the spintronic device according to claim 10.

19. A spintronic device comprising: A multilayer structure having a negative spin polarization and a negative anisotropy field, the multilayer structure comprising a plurality of alternating first and second layers in contact with each other, wherein each of the first layers comprises FeCr x 、FeV x 、FeTi x 、FeCr x V y 、FeCr x Ti y 、FeV x Ti y and FeCr x V y Ti z At least one of , wherein each of x, y, and z is a positive number, and each of the second layers comprises Co, wherein each of the first layers has a first thickness between 0.4 nm and 0.8 nm, and each of the second layers has a second thickness between 0.3 nm and 0.6 nm; and One or more layers are disposed above the multi-layer structure.

20. The spintronic device of claim 19, wherein the one or more layers include a capping layer disposed in contact with the multilayer structure, the capping layer being a FeCr-containing layer having the first thickness. x 、FeV x 、FeTi x 、FeCr x V y 、FeCr x Ti y 、FeV x Ti y or FeCr x V y Ti z Additional first floor.

21. The spintronic device of claim 19, wherein the multilayer structure is a free layer, a pinned layer, or a field generating layer, and wherein the negative anisotropy field of the multilayer structure is between -0.5 T and -0.8 T, and the effective magnetization of the multilayer structure is between 2.4 T and 2.8 T.

22. The spintronic device of claim 19, wherein each of the second layers further comprises one or more of Cr, V, and Ti.

23. A magnetic media drive comprising the spintronic device according to claim 19.

24. A magnetoresistive random access memory device comprising the spintronic device according to claim 19. 25 . A magnetic sensor comprising the spintronic device according to claim 19 .

26. A magnetic recording head comprising the spintronic device according to claim 19.

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