164 results about "Magnetic phase" patented technology

Apparatus and methods are described including a ventricular assist device that includes an impeller configured to be placed inside a left ventricle of a subject. A driving magnet is coupled to a motor and is rotated by the motor. A driven magnet is magnetically coupled to the driving magnet and is rotated by the driving magnet. A drive cable extends from the driven magnet and imparts rotational motion from the driven magnet to the impeller. A set of sensors is configured to detect a magnetic phase difference between the driven magnet and the driving magnet. A computer processor receives the detected magnetic phase difference and determines a physiological parameter of the subject, at least partially in response thereto. Other applications are also described.

The invention belongs to the field of magnetic materials, and particularly discloses europium-based silicate as well as a preparation method and application thereof. The general chemical formula of the europium-based silicate is Eu2SiO4, and the europium-based silicate is subjected to secondary magnetic phase change from a paramagnetic state to a ferromagnetic state at the magnetic phase change temperature of 5.8 K; and at the temperature of 5.5 K, when the magnetic field change is 0-2T, the maximum magnetic entropy change is greater than 10J. Kg <-1 >. K <-1 >. The europium-based silicate disclosed by the invention generates paramagnetic to ferromagnetic phase change near the liquid helium temperature, is accompanied by a low-magnetic-field giant magnetothermal effect near the magnetic phase change temperature, shows large magnetic entropy change and refrigerating capacity near the liquid helium temperature, and has a wide application prospect in the field of magnetic refrigeration in a liquid helium temperature region.

The invention provides a neodymium iron boron sintered magnet and a preparation method and application thereof. The neodymium iron boron sintered magnet comprises the following components: R, wherein the mass content of R is 28-33wt%; r comprises Nd and Ce, and optionally comprises or does not comprise at least one of Pr, Dy, Tb, Ho and Gd; m, wherein the mass content of the M is 1.5-2.5 wt%; b, the mass content of the B is 0.95 to 1.05 wt%; the mass content of the Ti ranges from 0.1 wt% to 0.25 wt%; fe is the balance; in the neodymium iron boron sintered magnet, the mass content of Ce is 0.3-5 wt%. By accurately controlling the main alloy element components, the generation of a soft magnetic phase in main phase grains is avoided; and meanwhile, the element components of the auxiliary alloy are optimized, and the dosage ratio of the main alloy to the auxiliary alloy is adjusted, so that main phase grains are refined, a fine titanium-rich phase which is dispersed and distributed is formed in a grain boundary phase, and the magnetic performance of the product is improved.

The invention provides a method for preparing H2-CO energy gas from steel slag, and belongs to the field of metallurgy and solid waste treatment. The preparation method comprises the following specific preparation steps: step 1, blowing weak oxidizing gas to the liquid level of the steel slag in a molten state to oxidize FeO in the steel slag, so that hydrogen and carbon monoxide gas are generated while ferric oxide is converted into a magnetic phase which is easy to separate; and 2, separating and collecting the reacted gas. After the steps, the energy gas containing H2 and CO is finally generated for recycling. Through the treatment steps provided by the invention, (1) CO2 is absorbed and converted into CO energy gas, and carbon emission is reduced; (2) waste heat of the steel slag is utilized, water vapor is converted into clean energy H2, and the hydrogen production cost is remarkably reduced; and (3) the injection proportion of H2O-CO2 gas is regulated and controlled, and the generation rate of H2-CO is remarkably increased.

The invention provides a magnetic code disc film material and a preparation method and application thereof. By introducing the TiN layer, a proper amount of nitrogen atoms can enter lattice gaps of iron, electron cloud distribution of iron atoms is changed, and the magnetic moment of the iron atoms is changed; the magnetic moment of Fe atoms can be influenced by N atoms and crystal structures, an alpha-Fe8N phase is formed in FeCoCr through introduction of N ions, the average magnetic moment of each Fe atom in the alpha-Fe8N phase is 2.4 mu B, alpha-Fe8N is a metastable phase, a sample can finally form stable gamma '-Fe4N through annealing, and the magnetic moment of the stable gamma'-Fe4N is generally about 2.5 mu B-2. 7 mu B and is higher than the magnetic moment 2.2 mu B of the Fe atoms in metal Fe; besides, Ti forms a Ti-Fe weak magnetic phase pinning magnetic domain wall in the FeCoCr thin film, and the coercive force and residual magnetism of the FeCoCr layer can be effectively improved at the same time through the method.

The invention relates to a method for producing a highly coercive magnet, the method comprising the following steps: a) providing: - a 1st powder comprising grains of a TR2Fe14B magnetic phase; - a 2nd powder comprising heavy rare earths and grains of a TR2Fe14B magnetic phase; b) the 2nd powder is subjected to a hydrogenation-disproportionation treatment; c) the 1st powder is mixed with the 2nd powder obtained at the end of step b); d) the mixture obtained at the end of step c) is subjected to a compacting step so as to obtain a compacted part; e) the compacted part obtained at the end of step d) is subjected to a presintering step; f) the presintered part obtained at the end of step e) is subjected to a sintering step.

The invention discloses a preparation method of a high-frequency and high-stability carbonyl ferromagnetic powder core, and belongs to the field of magnetic functional materials. On the basis of organic and inorganic composite coating, a uniform and high-resistance SiO2 insulating coating layer is formed on the surface of carbonyl iron particles by adopting a simplified insulating coating process, and the process does not need to adopt a silane coupling agent to perform surface modification on carbonyl iron powder so as to control the thickness of the SiO2 coating layer within a reasonable interval; weakening of the magnetic performance of the magnetic powder core caused by introduction of the non-magnetic phase is reduced to the maximum extent; the formed magnetic powder core does not need to be subjected to heat treatment, the onion layered special structure of the carbonyl iron powder particles is prevented from being damaged, the preparation process is simplified, operability is high, and the raw material cost is low. According to the preparation method, the bulk resistivity of the material is greatly improved, the magnetic core loss under the high-frequency condition is reduced, the quality factor, the direct-current anti-saturation characteristic, the magnetic conductivity temperature coefficient and the magnetic conductivity frequency change rate of the carbonyl ferromagnetic powder core are optimized, and the prepared magnetic powder core obtains high stability within the high-frequency range of 1-40 MHz.

The invention discloses a method for predicting the room-temperature magnetic performance of a neodymium iron boron permanent magnet, which is a prediction method based on practice and theoretical analysis, the prediction method deforms an existing residual magnetism and coercive force theoretical formula, and the form is changed into a form containing phase composition parameters based on actual deformation from a theoretical aesthetic form. According to the prediction method, a residual magnetism and coercive force calculation model is established by calculating the proportion of the main phase (NdFeB) to the non-magnetic phase (Non-magnetic Phase), simple, efficient and accurate prediction of the room-temperature magnetic performance of the neodymium-iron-boron permanent magnet is achieved, the non-magnetic phase composition and components which cannot be quantitatively analyzed can be bypassed, and the prediction accuracy of the room-temperature magnetic performance of the neodymium-iron-boron permanent magnet is improved. The influence of the components of the neodymium-iron-boron permanent magnet on the performance is simply and clearly displayed and calculated from a more macroscopic perspective, and a universal and quantitative rapid solution can be provided for component design and process design of various neodymium-iron-boron permanent magnets.

The invention relates to a cerium-iron-boron permanent magnet material with low content of a non-magnetic phase CeFe2 and a preparation method of the cerium-iron-boron permanent magnet material. The cerium-iron-boron permanent magnet material is composed of the following components in percentage by atom: 11%-17% of Ce, 70%-80% of Fe, 5%-10% of B, 0.1%-3% of Co, 0.1%-3% of Zr and 0.1%-5% of La. The preparation method comprises the following steps of S1, smelting, wherein Ce, La, Fe, Co, Zr and FeB are prepared into a CeLaFeCoZrB alloy cast ingot through electric arc smelting according to the atomic percent composition; s2, melt-spinning: crushing the CeLaFeCoZrB alloy ingot prepared in the S1, and then preparing an alloy strip by using a melt rapid quenching method; and S3, magnetic field annealing: performing vacuum annealing on the alloy strip prepared in S2, wherein the annealing temperature is 2-12K below the Curie temperature Tc of the alloy. Compared with the prior art, the method has the advantages that the phase volume fraction of the non-magnetic CeFe2 phase in the cerium-iron-boron permanent magnet material alloy is remarkably reduced, and the residual magnetism and the maximum magnetic energy product of the alloy are improved.

The invention discloses an all-component comprehensive utilization method for limonite type laterite-nickel ore, and belongs to the technical field of mineral processing and metallurgy. According to the method, multi-stage preheating and selective reduction are combined, accurate regulation and control of ore phase conversion are achieved by optimizing temperature and atmosphere conditions, metallic nickel and cobalt generated through reduction form a stable complex in the ammonia leaching process, and magnetite serves as an indissolvable magnetic phase to be left in slag. The reaction temperature is effectively reduced, the energy consumption is reduced, and the gas-solid mass transfer efficiency and the heat transfer efficiency are remarkably improved. The mineral structure is regulated and controlled through selective reduction, the adverse effects of excessive reduction, sintering, follow-up leaching difficulty and the like of iron oxide in the high-temperature roasting process of a traditional rotary kiln are avoided, and efficient selective leaching of nickel and cobalt and recovery and enrichment of magnetic iron ore are achieved. And meanwhile, the nickel and cobalt leaching efficiency is remarkably improved, interference of iron impurities on a leaching solution is reduced, and an economical and feasible new technical path is provided for resource comprehensive utilization and green metallurgy development of the limonite type laterite-nickel ore.

The invention discloses a method for regulating and controlling magnetic anisotropy of a Cr-based MXene material through charges. The method comprises the following steps: synthesizing an MAX precursor; the MAX precursor is subjected to etching and stripping, and a single-layer Cr-based MXene nanosheet is obtained; on the basis of a single-layer Cr-based MXene nanosheet, a substrate, an electrode and ionic liquid are used for synthesizing and regulating a Cr-based MXene material charge-doped ionic liquid gate structure. The method has the remarkable effects that the magnetic anisotropy (MAE) of the Cr2TiC2O2 material is improved through charge doping, the magnetic easy axis direction is regulated and controlled, the magnetism and the magnetic phase change can be accurately regulated, the magnetic order temperature of the material is remarkably improved, and the application potential of the material in a high-temperature environment is widened.

The utility model provides steel sheet pile correcting equipment convenient to fix, and relates to the technical field of steel sheet pile correcting equipment. The steel sheet pile correcting equipment convenient to fix comprises a machine body, a base is arranged at the bottom end of the machine body, a guide rail is arranged at the top end of the base, a pressing roller is arranged in the machine body, and a motor is arranged on the outer surface of the machine body. A supporting device is arranged at one end of the outer surface of the machine body, the supporting device comprises two groove rods, a U-shaped plate is arranged on the outer surface of each U-shaped rod, and a magnetic plate is arranged on the outer surface of each U-shaped plate. When the steel sheet pile moves, the magnetic plate on the outer surface of the U-shaped plate magnetically attracts the steel sheet pile to drive the U-shaped rod to slide on the inner wall of the groove rod along with the steel sheet pile, the lower portion of the steel sheet pile is supported through the U-shaped rod and the U-shaped plate, the position and angle of the steel sheet pile are fixed conveniently, and the angle of the end, away from the machine body, of the steel sheet pile is prevented from inclining as much as possible; the correction effect on the steel sheet pile is influenced.

The invention discloses a FeNi soft magnetic composite material based on tetrabutyl orthosilicate hydrolysis coating and a preparation method of the FeNi soft magnetic composite material. According to the method, through a controllable sol-gel process, tetrabutyl orthosilicate is hydrolyzed to generate SiO2 gel, then a uniform and ultrathin SiO2 gel layer is generated on the surface of FeNi powder in situ, and then heat treatment densification is performed to obtain the FeNi soft magnetic composite material coated with SiO2 in an insulation mode. The SiO2 insulating layer is firmly combined with the matrix metal powder, the thermal stability is good, high frequency and high resistivity are achieved, and meanwhile dilution of non-magnetic relative magnetic performance is reduced to a great extent. The final magnetic core is obtained through compression molding and annealing heat treatment, has the excellent characteristics of high effective magnetic conductivity and low high-frequency magnetic core loss, and is particularly suitable for various efficient and miniaturized power electronic devices in the MHz frequency band.

The invention discloses a high-strength and high-saturation soft magnetic alloy composite material and a preparation method thereof. The soft magnetic alloy material is smelted to obtain alloy liquid, first cooled in a nitrogen atmosphere, and then immediately placed in cooling water to cool to obtain soft magnetic alloy powder, surface modified to obtain modified powder, mixed with glass powder under stirring to obtain mixed powder, granulated to obtain granules, pressed the granules to obtain magnetic rings, and sintered to obtain the magnetic rings. The invention refines the grains inside the metal by rapidly cooling the metal powder to increase the material's ability to resist direct current attenuation, so that the material can be used under a larger saturation current. During surface modification, the glass powder is more tightly attached to the powder by high-speed stirring, and then the glass powder is evenly distributed in the oxide generated between the particles by pressure sintering to form a composite oxide layer, thereby improving the bonding force between the particles and obtaining a more uniform non-magnetic phase to improve the material's ability to resist direct current attenuation, thereby preparing a high-strength and high-saturation soft magnetic alloy composite material.

Permanent magnets and method of making the same are provided. The magnets include a magnetic layer having an insulation layer disposed thereon. The insulation layer is formed via additive manufacturing techniques such as laser melting such that it has discrete phases including a magnetic phase and an insulating phase.

The application discloses a micro patch power inductor based on micro area 3D printing and a preparation method thereof, and belongs to the technical field of 3D printing micro inductor devices. The preparation method uses Fe-based soft magnetic powder as a magnetic phase raw material to prepare a 3D printing support medium; a micro area 3D printing method is used to print at least one group of coils and lead-out ends of the coils in the support medium, so that the coils and the lead-out ends are completely embedded in the support medium, and an inductor blank is formed; after the support medium and the inductor blank are separated, the inductor is prepared, the inductor is cleaned and silver-plated; the inductor after silver-plating is annealed, and a micro patch power inductor is prepared. The method can print micron-level coils, the prepared inductor has a smaller volume, can reach a wire diameter of 10 um, has a good yield, can be annealed, the magnetic permeability of the magnetic material is improved, the magnetic hysteresis loss is reduced, and the prepared inductor has higher electromagnetic performance under the same volume condition.

The present invention discloses a method for preparing high-performance composite magnetic powder, which belongs to the field of magnetic material technology. The preparation method comprises: firstly preparing Sm2Fe 17 The invention relates to a method for preparing a magnetic particle and nitriding it to obtain a samarium iron nitrogen particle magnet; and during the high-energy ball milling process of metal Sm and metal Co, a mixture of the samarium iron nitrogen particle magnet and gasoline is sprayed into a mixed powder of metal Sm and metal Co in a spray manner, so that Sm and Co react chemically to achieve the synthesis of a hard magnetic phase Sm-Co phase, simplifying the preparation process, eliminating the smelting process, and avoiding the volatilization of Sm; finally, the magnetic mixed powder is subjected to a primary and secondary laser fast sintering nitriding and tempering heat treatment in a nitrogen atmosphere to finally obtain a high-performance composite magnetic powder. The method of the present invention has a simple process, is easy to form, reduces costs, and is conducive to the application of high-performance magnets in more permanent magnet devices.

The invention discloses a primary phase change magnetic refrigeration alloy material and a preparation method thereof, the chemical formula of the alloy material is La0. 9Pr0. 1Fe12B6, and the alloy material has magnetocrystalline coupling and magnetoelastic coupling properties at the same time. The preparation method comprises the following steps: 1, preparing raw materials according to the chemical formula of the alloy material, and melting the prepared raw materials in a tungsten electrode non-consumable electric arc furnace to obtain an alloy ingot sample; and secondly, the ingot casting sample is subjected to heat treatment, and the La0. 9Pr0. 1Fe12B6 alloy material is obtained. According to the invention, the chemical formula of La1-xPrxFe12B6 is reasonably designed, the primary phase change magnetic refrigeration La1-xPrxFe12B6 alloy material with a lower critical magnetic field of magnetic field induced variable magnetic phase change is realized, and the material also has double coupling properties of magnetocrystalline coupling and magnetoelastic coupling.

The utility model provides a magnetic anchor buckle which comprises an elastic buckle, the elastic buckle comprises a first side edge and a second side edge, the first side edge is perpendicular to the second side edge, one end of the first side edge is connected with one end of the second side edge, the other end of the first side edge and the other end of the second side edge are provided with elastic pieces, and the elastic pieces are connected with the first side edge and the second side edge. The elastic sheet is used for clamping a ground pin, and the first side edge and / or the second side edge are / is made of metal; the magnet assembly comprises a magnet; the first side edge and / or the second side edge can magnetically attract the magnet, so that the elastic buckle is detachably connected with the magnet assembly. According to the embodiment of the utility model, the magnet assembly is arranged on the aluminum profile, the elastic buckle is buckled on the foot margin, and the foot margin can be quickly mounted through magnetic attraction between the magnet assembly and the elastic buckle, alignment is not needed, mounting and dismounting are convenient, and the mounting speed is high.

The invention relates to temperature-control concrete for regulating and controlling distribution of phase-change lightweight aggregate based on a magnetic field and a preparation method thereof. The concrete comprises the following components in percentage by mass (kg / m < 3 >): 730-870% of magnetic phase-change lightweight aggregate; 240 to 380 parts of shale pottery sand; 450 to 550 parts of cement; 40-60 parts of silica fume; 0-30 parts of fly ash; 5-7 parts of a water reducing agent; 0 to 61.4 parts of floating beads; 20 to 15 parts of nano SiO; 50 to 80 parts of water; and 1.5 to 7.5 parts of carbon fiber. The preparation method comprises the following steps: 1, designing a magnetic field device to cover the whole concrete pouring area; 2, mixing the six magnetic phase change aggregates; 3, the shale pottery sand is pre-wetted to a saturated surface dry state; 4, uniformly stirring the silica fume, the cement, the fly ash, the floating beads and the nano SiO2; 5, adding the rest components in two batches; sixthly, stirring the concrete, pouring the concrete into the mold, and starting the magnetic field device at the same time; and 8, after initial setting of the concrete, closing the magnetic field device and maintaining.

The invention belongs to the technical field of permanent magnet materials, and relates to a nanocrystalline composite permanent magnet material and a manufacturing method thereof. The nanocrystalline composite permanent magnet material comprises a hard magnetic phase and a soft magnetic phase, the grain size of the hard magnetic phase and the grain size of the soft magnetic phase are independently smaller than or equal to 25 nm; the content of the soft magnetic phase is greater than 40 wt.%; the hard magnetic phase comprises a hard magnetic main phase, the proportion of the hard magnetic main phase in the hard magnetic phase is larger than 50 wt.%, and the hard magnetic main phase is a rare earth cobalt-based hard magnetic phase. The maximum magnetic energy product of the nanocrystalline composite permanent magnet material obviously exceeds the theoretical upper limit of the magnetic energy product of the single-phase hard magnetic material of the hard magnetic main phase. The giant magnetic energy product effect of the nanocrystalline composite permanent magnet material is realized by strictly controlling the raw material ratio and the preparation process.

The invention discloses a method for producing Fe-phase-free alpha ''-Fe16N2 powder through a one-step method, and belongs to the technical field of magnetic materials. The method comprises the steps that iron ore concentrate is subjected to two-stage wet grinding activation to obtain nanoscale iron ore concentrate powder slurry, the nanoscale iron ore concentrate powder slurry is subjected to drying and pre-oxidation treatment to obtain nanoscale iron ore concentrate powder with the surface layer being Fe2O3, then the nanoscale iron ore concentrate powder with the surface layer being Fe2O3 is placed in an ammonia-hydrogen mixed gas environment to be subjected to a reduction-nitridation reaction, and the iron ore concentrate powder with the surface layer being Fe2O3 is obtained. According to the method, the instantaneous high activity of hydrogen reduction iron is better utilized, efficient and sufficient nitridation of iron can be achieved, and compared with an existing conventional technology for preparing alpha ''-Fe16N2 through a reduction-nitridation two-step method, the method has the technical advantages that a product is free of a soft magnetic phase, the permanent magnet performance is good, and the technology is simple and convenient.

The invention discloses a heat release type sponge capable of effectively adsorbing crude oil in a low-temperature environment as well as a preparation method and application of the heat release type sponge, and belongs to the technical field of oil-water separation application. According to the super-hydrophobic sandwich-structured light / magnetic heat energy storage composite sponge, firstly, the surface of the sponge is soaked with ink, and after further surface hydrophobic modification, the outer-layer super-hydrophobic oil absorption sponge is obtained; then packaging the molten phase-change material into a hose fixed with a magnetic metal wire by adopting a simple filling method to obtain a magnetic phase-change core material; finally, the outer-layer super-hydrophobic photo-thermal oil absorption sponge and the magnetic phase change core material are assembled into the sandwich-structured photo-thermal / magnetic thermal energy storage composite sponge, the coupled phase change material can reduce energy consumption in the crude oil adsorption process to a certain extent by slowly releasing stored heat, and low-energy-consumption and efficient recovery of high-viscosity crude oil is achieved.

An R-T-B sintered magnet of the present disclosure includes a principal phase that comprises an R2T14B compound and a grain boundary phase located in a grain boundary portion of the principal phase. The atomic ratio of B to T in the R-T-B sintered magnet is lower than the atomic ratio of B to T in the chemical stoichiometric composition of the R2T14B compound. The relationships 26.0 mass% ≤ ([Nd] + [Pr] + [Ce] + [La] + [Dy] + [Tb]) - 12 ([O] + [C]) ≤ 27.7 mass%, 0.85 mass% ≤ [B] ≤ 0.94, 0.05 mass% ≤ [O] ≤ [0.30] mass%, 0.05 mass% ≤ [M] ≤ 2.00 mass%, [Tb] ≤ 0.20 mass%, and [Dy] ≤ 0.30 mass% are satisfied. A section is included in which at least the Nd concentration or the Pr concentration gradually decreases gradually from the front surface of the magnet toward the interior of the magnet.

The invention discloses a method for high-precision determination of magnetic moment of micro-nano magnetic structure based on electron holography, comprising the following steps: S1, observing a sample under a transmission electron microscope, and obtaining two electron holograms before and after magnetization reversal by tilting the sample; S2, in an image processing program, reconstructing a phase map from the two holograms in step S1, subtracting them from the center, and halving them to obtain a sample magnetic phase map; S3, performing circular loop integral fitting and extrapolation to zero on the magnetic phase map obtained in step S2 to obtain an induced magnetic moment, and then obtaining a magnetic moment value according to the relationship between the magnetic induced moment and the magnetic moment. The method of the invention can realize quantitative measurement of high-precision magnetic moment at micro-nano scale.

A device and method for high speed metamagnetic resistive switching provides a metamagnetic phase transitioning (MPT) portion formed on a substrate between terminals. The MPT portion is tuned for temperature-responsive transitions between magnetic phases through a transition phase. The phases are delineated by phase boundaries each traversed at different critical temperatures depending on direction of traversal. The critical temperatures of each phase boundary are mutually offset by a hysteretic shift. The MPT portion is boosted across one phase boundary responsive to thermal actuation pulsed in a first direction to reach or exceed both critical temperatures of that phase boundary in the first direction, and boosted across the other phase boundary responsive to thermal actuation pulsed in a second direction to reach or exceed both critical temperatures of that phase boundary in the second direction. The electrical conduction path is thereby adjusted in resistivity for switching between ON and OFF states.

The present disclosure relates to an anisotropic bulk magnet and a method for manufacturing the same. The anisotropic bulk magnet has a high fraction of a (Re,Ce)2(Fe,Ti)14B phase (magnetic phase), a low fraction of a (Re,Ce)Fe2 phase (non-magnetic phase), a fine crystal grain size, an excellent degree of crystal grain alignment, and a high rare earth element content at an interface of the crystal grain, and therefore, may have excellent magnetic properties such as coercivity and maximum magnetic energy product.

The invention discloses a method and a device for generating power by using impact energy, and the method comprises the steps: driving the magnetic phase change of a pressure-sensitive magnetic composite material by using isotropic pressure intensity change, so that the magnetic flux density of the pressure-sensitive magnetic composite material is changed; the pressure-sensitive magnetic composite material comprises a magnetic intermetallic compound Mn-Co-Si-Ge and a solid pressure conduction medium. According to the invention, the impact force in the uniaxial direction is converted into isotropic pressure change by utilizing a solid pressure conduction medium, so that the Mn-Co-Si-Ge alloy particle has no special requirement on the mechanical strength and has the advantage of high bearing capacity; and the used Mn-Co-Si-Ge alloy is a transition intermetallic compound, so that the material cost is relatively low.

A multilayer coil component includes a multilayer body in which a plurality of insulating layers are stacked in a stacking direction and a coil inside, and outer electrodes on surfaces of the multilayer body and electrically connected to the coil. The insulating layers have a magnetic phase having spinel structure containing at least Fe, Ni, Zn, and Cu and a non-magnetic phase containing at least Si. When grain sizes D50 and D90 of crystal grains constituting the magnetic phase are respectively defined as equivalent-area circle diameters of 50% and 90% on a cumulative sum basis in a cumulative distribution of equivalent-area circle diameters of the crystal grains, the grain size D50 is from 50 nm to 750 nm, and the grain size D90 is from 200 nm to 1500 nm.

A rare-earth permanent magnet powder, wherein the rare-earth permanent magnet powder comprises 4 to 12 atomic% Nd, 0.1 to 2 atomic% C, 10 to 25 atomic% N and 62.2 to 85.9 atomic% T, wherein the T is Fe or FeCo and the main phase of the rare-earth permanent magnet powder is a hard magnetic phase with a TbCu7 structure; wherein the rare-earth permanent magnet powder further comprises 1 to 5 atomic% of element A and 0.1 to 2 atomic% of element boron; where the element A is Zr and / or Hf, the ratio of the content of the element boron to the content of the element A is 0.1 to 0.5; where the content of the element Nd and the element A in the rare-earth permanent magnet powder is 4 to 12 atomic % of the total content of the rare-earth permanent magnet powder, and the ratio of the content of the element C to the sum of the content of the element Nd and the element A in the rare-earth permanent magnet powder is 0.05 to 0.12.