Abstract: A method of producing a motor core includes preparing a soft magnetic plate containing a transition metal element, preparing a modifying member containing an alloy having a melting point lower than a melting point of the soft magnetic plate, bringing the modifying member into contact with a part of a plate surface of the soft magnetic plate, causing the modifying member to diffuse and penetrate into the soft magnetic plate from a contact surface between the soft magnetic plate and the modifying member and forming a hard magnetic phase-containing part in a part of the soft magnetic plate, and laminating a plurality of soft magnetic plates on each other after the modifying member is brought into contact with the part of the plate surface of the soft magnetic plate.

Abstract: To provide a rare earth magnet having excellent coercive force and a production method thereof. A rare earth magnet, wherein the rare earth magnet comprises a magnetic phase containing Sm, Fe, and N, a Zn phase present around the magnetic phase, and an intermediate phase present between the magnetic phase and the Zn phase, wherein the intermediate phase contains Zn and the oxygen content of the intermediate phase is higher than the oxygen content of the Zn phase; and a method for producing a rare earth magnet, including mixing a magnetic raw material powder having an oxygen content of 1.0 mass % or less and an improving agent powder containing metallic Zn and/or a Zn alloy, and heat-treating the mixed powder.

Abstract: A rare earth magnet in which the amount used of a heavy rare earth element is more reduced while maintaining enhancement of the coercive force, and a producing method thereof are provided. The rare earth magnet of the present disclosure has a main phase 10 and a grain boundary phase 20. The main phase 10 has a composition represented by R12T14B. The main phase 10 has a core part 12 and a shell part 14. Denoting the abundances of R2 and Ce (R2 is heavy rare earth element) occupying 4f site of the shell part 14 as R24f and Ce4f, respectively, and denoting the abundances of R2 and Ce occupying 4g site of the shell part 14 as R24g and Ce4g, respectively, the rare earth magnet satisfies 0.44?R24g/(R24f+R24g)?0.70 and 0.04?(Ce4f+Ce4g)/(R24f+R24g). The rare earth magnet-producing method of the present disclosure uses a modifier containing at least R2 and Ce.

Abstract: There is provided a manufacturing method for a rare earth magnet, including forming a zinc-containing coating film on a surface of a particle of a samarium-iron-nitrogen-based magnetic powder to obtain a coated powder, subjecting the coated powder to compression molding to obtain a compacted powder body, and subjecting the compacted powder body to pressure sintering, in which a coating rate of the coating film with respect to an entire surface of the particle of the coated powder is 96% or more, and the formation of the coating film and the pressure sintering of the compacted powder body is carried out in a vacuum or an inert gas atmosphere, and the compression molding of the coated powder is carried out in the atmospheric air.

Abstract: A rare-earth magnet and a method of manufacturing the same are provided. The method includes: preparing Sm-Fe-N magnetic powder; preparing reforming material powder containing metallic zinc; mixing the magnetic powder and the reforming material powder to obtain mixed powder; subjecting the mixed powder to compression molding in a magnetic field to obtain a magnetic-field molded body; subjecting the magnetic-field molded body to pressure sintering to obtain a sintered body; and subjecting the sintered body to heat treatment. A content proportion of the metallic zinc in the reforming material powder is 10 to 30% by mass with respect to the mixed powder. When a temperature and time in conditions for the heat treatment are defined as x° C. and y hours, respectively, the formulas y??0.32x+136 and 350?x?410 are met.

Abstract: The present disclosure provides a rare earth magnet having a main phase and a grain boundary phase and a manufacturing method therefor. In the rare earth magnet of the present disclosure, the overall composition is represented by a formula (R1(1-x-y)LaxCey)u(Fe(1-z)Coz)(100-u-w-v)BwM1v. (R1 is a predetermined rare earth element, M1 is a predetermined element, and the followings are satisfied, 0.05?x?0.25, 0.5?y/(x+y)?0.50, 13.5?u?20.0, 0?z?0.100, 5.0?w?10.0, and 0?v?2.00). The main phase has an R2Fe14B-type crystal structure, and the average grain size and the volume fraction of the main phase are respectively 1.0 ?m to 20.0 ?m and 80.0% to 90.0%. The main phase and the grain boundary phase satisfy, (the existence proportion of La in the grain boundary phase)/(the existence proportion of La in the main phase)>1.30.

Abstract: To provide an R—Fe—B-based rare earth magnet excellent in the squareness and magnetic properties at high temperatures, and method for producing thereof. The present disclosure relates to a rare earth magnet including a main phase 10 and a grain boundary phase 20 present around the main phase 10, and a method for producing thereof. In the rare earth magnet of the present disclosure, the overall composition is represented, in terms of molar ratio, by the formula: (R1(1-x)Lax)y(Fe(1-z)Coz)(100-y-w-v)BwM1v, wherein R1 is a predetermined rare earth element, M1 is a predetermined element, 0?x?0.1, 12.0?y?20.0, 0.1?z?0.3, 5.0?w?20.0, and 0?v?2.0. The main phase 10 has an R2Fe14B-type crystal structure, the average particle diameter of the main phase 10 is less than 1 ?m, and the volume ratio of a phase having an RFe2-type crystal structure in the grain boundary phase 20 is 0.40 or less relative to the grain boundary phase 20.

Abstract: A magnetic material according to the present disclosure includes a main phase having an R2T14B type crystal structure (R is a rare earth element and T is a transition metal element). The main phase has a composition represented by ((Nd, Pr)(1-x-y)LaxR1y))2((Fe(1-z-w)(Co, Ni)zMw))14B (where, R1 is a rare earth element other than Nd, Pr, and La, M is an element other than Fe, Co, Ni, and a rare earth element, and the like, and 0.25?x?1.00, 0?y?0.10, 0.15?z?0.40, and 0?w?0.1 are satisfied). A manufacturing method of the magnetic material according to the present disclosure includes melting a raw material containing the elements constituting the main phase and solidifying the melted raw material.

Abstract: An Sm-Fe-N-based magnetic material according to the present disclosure includes a main phase having a predetermined crystal structure. The main phase has a composition represented by (Sm(1-x-y-z)LaxCeyR1z)2(Fe(1-p-q-s)CopNiqMs)17Nh (where, R1 is predetermined rare earth elements and the like, M is predetermined elements and the like, and 0.04?x+y?0.50, 0?z?0.10, 0?p+q?0.10, 0?s?0.10, and 2.9?h?3.1 are satisfied). A crystal volume of the main phase is 0.833 nm3 to 0.840 nm3. A manufacturing method of the Sm-Fe-N-based magnetic material according to the present disclosure includes nitriding a magnetic material precursor including a crystal phase having a composition represented by (Sm(1-x-y-z)LaxCeyR1z)2(Fe(1-p-q-s)CopNiqMs)17.

Abstract: An Sm—Fe—N-based magnetic material according to the present disclosure includes a main phase having a predetermined crystal structure. The main phase has a composition represented by a molar ratio formula (Sm(1-x-y-z)LaxCeyR1z)2(Fe(1-p-q-s)CopNiqMs)17Nh (where, R1 is a predetermined rare earth element, M is a predetermined element, and 0?x+y<0.04, 0?z?0.10, 0<p+q?0.10, 0?s?0.10, and 2.9?h?3.1 are satisfied). A lattice volume of the main phase is 0.830 nm3 to 0.840 nm3, and a density of the main phase is 7.70 g/cm3 to 8.00 g/cm3.

Abstract: To provide an R—Fe—B-based rare earth magnet excellent in the squareness and magnetic properties at high temperatures, and a production method thereof. The present disclosure provides a rare earth magnet including a main phase 10 and a grain boundary phase 20 present. The overall composition of the rare earth magnet of the present disclosure is represented, in terms of molar ratio, by the formula: (R1(1-x)Lax)y(Fe(1-z)Coz)(100-y-w-v)BwM1v, wherein R1 is one or more predetermined rare earth elements, and M1 is one or more predetermined elements, and wherein 0.02?x?0.1, 12.0?y?20.0, 0.1?z?0.3, 5.0?w?20.0, and 0?v?2.0. The main phase 10 has an R2Fe14B-type crystal structure, the average particle diameter of the main phase 10 is from 1 to 10 ?m, and the volume ratio of a phase having an RFe2-type crystal structure in the grain boundary phase 20 is 0.60 or less relative to the grain boundary phase 20.

Abstract: A rare earth magnet includes a main phase and a particle boundary phase and in which an overall composition is represented by a formula, (R2(1-x)R1x)yFe(100-y-w-z-v)CowBzM1v.(R3(1-p)M2p)q.(R4(1-s)M3s)t, where R1 is a light rare earth element, R2 and R3 are a medium rare earth element, R4 is a heavy rare earth element, M1, M2, M3 are a predetermined metal element. The main phase includes a core portion, a first shell portion, and a second shell portion. The content proportion of medium rare earth element is higher in the first shell portion than in the core portion, the content proportion of medium rare earth element is lower in the second shell portion than in the first shell portion. The second shell portion contains heavy rare earth elements.

Abstract: The production method of a rare earth magnet of the present disclosure includes a coated magnetic powder preparation step, a mixed powder preparation step, and a pressure sintering step. In the coated magnetic preparation step, a zinc-containing coating 12 is formed on the particle surface of a samarium-iron-nitrogen-based magnetic powder to obtain a coated magnetic powder 14. In the mixed powder preparation step, a binder powder 20 having a melting point not higher than the melting point of the coating 12 and the coated magnetic powder 14 are mixed to obtain a mixed powder. In the pressure sintering step, denoting as T1° C. the temperature at which the peak disappears in an X-ray diffraction pattern of the binder powder 20 and as T2° C. the temperature at which the magnetic phase in the samarium-iron-nitrogen-based magnetic powder 10 decomposes, the mixed powder is pressure-sintered at T1° C. or more and (T2?50)° C. or less.

Abstract: A method for producing a rare earth magnet, including preparing a melt of a first alloy having a composition represented by (R1vR2wR3x)yTzBsM1t (wherein R1 is a light rare earth element, R2 is an intermediate rare earth element, R3 is a heavy rare earth element, T is an iron group element, and M1 is an impurity element, etc.), cooling the melt of the first alloy at a rate of from 100 to 102 K/sec to obtain a first alloy ingot, pulverizing the first alloy ingot to obtain a first alloy powder having a particle diameter of 1 to 20 ?m, preparing a melt of a second alloy having a composition represented by (R4pR5q)100-uM2u (wherein R4 is a light rare earth element, R5 is an intermediate or heavy rare earth element, M2 is an alloy element, etc.), and putting the first alloy powder into contact with the melt of the second alloy.

Abstract: A rare earth magnet 100 including a main phase 10 and a grain boundary phase 20. The overall composition is represented by the formula: (R2(1-x)R1x)yFe(100-y-w-z-v)CowBzM1v.(R3(1-p)M2p)q. R1 is an element selected from Ce, La, Y, and Sc. R2 and R3 is an element selected from Nd, Pr, Gd, Tb, Dy, and Ho. M1 is a predetermined element, etc. M2 is a transition metal element, etc. The average particle dimeter of the main phase 10 is from 1 to 20 ?m. The main phase 10 has a core portion 12 and a shell portion 14. The thickness of the shell portion 14 is from 25 to 150 nm. The “a” is the ratio of the light rare earth element of the core portion 12 and the “b” is the ratio of the light rare earth element of the core portion 12. These satisfy 0?b?0.30 and 0?b/a?0.50.

Abstract: A rare earth magnet including a magnetic phase having the composition represented by (Nd(1?x?y)LaxCey)2(Fe(1?z)Coz)14B. When the saturation magnetization at absolute zero and the Curie temperature calculated by Kuzmin's formula based on the measured values at finite temperature and the saturation magnetization at absolute zero and the Curie temperature calculated by first principles calculation are respectively subjected to data assimilation. The saturation magnetization M(x, y, z, T=0) at absolute zero and the Curie temperature obtained by machine learning using the assimilated data group are applied again to Kuzmin's formula and the saturation magnetization at finite temperature is represented by a function M(x, y, z, T), x, y, and z of the formula in an atomic ratio are in a range of satisfying M(x, y, z, T)>M(x, y, z=0, T) and 400?T?453.

Abstract: A magnetic compound represented by the formula (R1(1-x)R2x)a(Fe(1-y)Coy)bTcMd wherein R1 is one or more elements selected from the group consisting of Sm, Pm, Er, Tm and Yb, R2 is one or more elements selected from the group consisting of Zr, La, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Ho and Lu, T is one or more elements selected from the group consisting of Ti, V, Mo, Si and W, M is one or more elements selected from the group consisting of unavoidable impurity elements, Al, Cr, Cu, Ga, Ag and Au, 0?x?0.7, 0?y?0.7, 4?a?20, b=100-a-c-d, 0<c<7.7, and 0?d?3, the magnetic compound having a ThMn12-type crystal structure, wherein the volume fraction of ?-(Fe, Co) phase is less than 12.3%.

Abstract: To provide a motor control method ensuring that dragging loss at the time of high rotation can be reduced. A motor control method, wherein a composite permanent magnet has a core part and a shell part, the Curie temperature of one of the core part and the shell part is Tc1 K, and the Curie temperature of another is Tc2 K, and wherein when the magnitude of the reluctance torque is equal to or greater than the magnitude of the magnet torque, the temperature of the composite permanent magnet is set at Ts K that is (Tc1?100) K or higher and lower than Tc2 K and when the magnitude of the reluctance torque is less than the magnitude of the magnetic torque, the temperature of the composite permanent magnet is set at lower than the temperature Ts K or Tc1 K, whichever is lower.

Abstract: A rare earth magnet includes a main phase, a grain boundary phase present around the main phase and an intermediate phase interposed between the main phase and the grain boundary phase, and has an overall composition that is represented by the formula ((Ce(1-x)Lax)(1-y)R1y)pT(100-p-q-r)BqM1r?(R21-zM2z)s (where, R1 and R2 are rare earth elements other than Ce and La, T is at least one selected from among Fe, Ni, and Co, M1 is an element having a small amount that does not influence magnetic characteristics, and M2 is an alloy element for which a melting point of R21-zM2z is lower than a melting point of R2). A total concentration of Ce and La is higher in the main phase than in the intermediate phase, and a concentration of R2 is higher in the intermediate phase than in the main phase.

Abstract: A method of producing a motor core includes preparing a soft magnetic plate containing a transition metal element, preparing a modifying member containing an alloy having a melting point lower than a melting point of the soft magnetic plate, bringing the modifying member into contact with a part of a plate surface of the soft magnetic plate, causing the modifying member to diffuse and penetrate into the soft magnetic plate from a contact surface between the soft magnetic plate and the modifying member and forming a hard magnetic phase-containing part in a part of the soft magnetic plate, and laminating a plurality of soft magnetic plates on each other after the modifying member is brought into contact with the part of the plate surface of the soft magnetic plate.