The permanent magnet includes: a main phase expressed by a composition formula: RM.sub.ZN.sub.X and having at least one crystal structure selected from the group consisting of a Th.sub.2Ni.sub.17 crystal structure, a Th.sub.2Zn.sub.17 crystal structure, and a TbCu.sub.7 crystal structure; and a sub phase having a phosphorus compound phase containing a phosphorus compound excluding a phosphoric acid compound.

Provided are a highly thermostable rare-earth permanent magnetic material, a preparation method thereof and a magnet containing the same. A composition of the rare-earth permanent magnetic material by an atomic percentage is as follows: SM.sub.xR.sub.aFe.sub.100-x-y-z-aM.sub.yN.sub.z, wherein R is at least one of Zr and Hf, M is at least one of Co, Ti, Nb, Cr, V, Mo, Si, Ga, Ni, Mn and Al, x+a is 7-10%, a is 0-1.5%, y is 0-5% and z is 10-14%.

A SmFeN-based magnetic material capable of enhancing saturation magnetization while suppressing a decrease in the anisotropic magnetic field as much as possible even when the use amount of Sm is reduced, and a production method thereof, are provided.

The magnetic material of the present disclosure includes a main phase having a predetermined crystal structure. The composition of the main phase is represented by (Sm.sub.(1-x-y-z)La.sub.xCe.sub.yR.sup.1.sub.z).sub.2(Fe.sub.(1-p-q-s)Co.sub.pNi.sub.qM.sub.s).sub.17N.sub.h, where R.sup.1 is a given rare earth element, etc. M is a given element, and 0.25x+y0.73, 0.25x0.73, x/(x+y)0.80, 0z0.10, 0.10p+q0.53, p+q1.45(x+y)0.5485, 0s0.10 and 2.9h3.3 are satisfied. The production method of the present disclosure includes nitriding a precursor including a crystal phase having a composition represented by (Sm.sub.(1-x-y-z)La.sub.xCe.sub.yR.sup.1.sub.z).sub.2(Fe.sub.(1-p-q-s)Co.sub.pNi.sub.qM.sub.s).sub.17.

An SmFeN-based magnetic powder includes particles containing Sm, Fe, and N as main components. The powder has a composition wherein a molar ratio of Sm to Fe (Sm/Fe) is 0.09 or more and 0.25 or less, a molar ratio of N to Fe (N/Fe) is 0.06 or more and 0.30 or less, and a Ca content in the powder is 0.002 mass % or less. When a cumulative 10% particle diameter is represented by D10, a cumulative 50% particle diameter is represented by D50, and a cumulative 90% particle diameter is represented by D90 in a volume-based particle size distribution according to a laser diffraction/scattering method, D50 is 2.0 to 11.0 m, and D10, D50, and D90 satisfy a relationship of the following formula: (D90D10)/D50<1.10. The SmFeN-based magnetic powder is advantageous in improving coercive force, containing few impurities, and improving the performance and manufacturability of a bonded magnet.

A SmFeN-based rare earth magnet more resistant to demagnetization than ever before in an environment where an external magnetic field is applied, particularly at high temperatures, and a production method thereof are provided. The present disclosure presents a production method of a rare earth magnet, including preparing a coated magnetic powder, compression-molding the coated magnetic powder in a magnetic field to obtain a magnetic-field molded body, pressure-sintering the magnetic-field molded body to obtain a sintered body, and heat-treating the sintered body, and a rare earth magnet obtained by the method. D.sub.50 of the magnetic powder in the coated magnetic powder is 1.50 m or more and 3.00 m or less, the content ratio of the zinc component in the coated magnetic powder is 3 mass % or more and 15 mass % or less, and the heat treatment temperature is 350 C. or more and 410 C. or less.

A rare-earth magnet and a method of manufacturing the same are provided. The method includes: preparing SmFeN 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 y0.32x+136 and 350x410 are met.

The magnet has a composition expressed by R.sub.pFe.sub.qM.sub.rCu.sub.tCo.sub.100-p-q-r-t. The magnet has a metallic structure including a main phase having a Th.sub.2Zn.sub.17 crystal phase. The main phase has crystal grains. 5% or less of the crystal grains having a grain diameter equal to or smaller than 10 m, 40% or less of the crystal grains having crystal orientation perpendicular to (001) plane of the Th.sub.2Zn.sub.17 crystal phase in a direction deviated 30 degrees or more relative to an axis of easy magnetization.

A method of manufacturing a permanent magnet comprises a solution heat treatment. The solution heat treatment includes: performing a heat treatment at a temperature T.sub.ST; placing a cooling member including a first layer and a second layer on the first layer between the heater and the treatment object so that the first layer faces the treatment object; and transferring the treatment object together with the cooling member to the outside of a heating chamber, and cooling the treatment object until a temperature of the treatment object becomes a temperature lower than a temperature T.sub.ST200 C. In the step of cooling the treatment object, a cooling rate until the temperature of the treatment object becomes the temperature T.sub.ST200 C. is 5 C./s or more.

In one embodiment, a permanent magnet includes a composition represented by R.sub.pFe.sub.qM.sub.rCu.sub.sCo.sub.100-p-q-r-s (R: rare earth element, M: at least one element selected from Zr, Ti and Hf, 10p13.5 atomic %, 28q40 atomic %, 0.88r7.2 atomic %, 4s13.5 atomic %), and a metallic structure in which a composition region having an Fe concentration of 28 mol % or more is a main phase. A Cu concentration in the main phase is 5 mol % or more.

A hard magnetic material formed of material powders made of a RFeN compound containing a light rare earth element as R, or material powders made of a FeN compound is used as material powders. There is formed a compact in which a density of the hard magnetic material powders differs between an outer face side portion and an inside portion of the compact such that a rate of progress of powder bonding due to microwave heating is higher in the inside portion of the compact than in the outer face side portion of the compact when an outer face of the compact is irradiated with microwaves. Then, the outer face of the compact is irradiated with the microwaves to cause the microwave heating, thereby bonding the hard magnetic material powders by oxide films which are formed on the hard magnetic material powders.