Provided are an anisotropic rare earth sintered magnet having a ThMn.sub.12-type crystal compound as a main phase and exhibits good magnetic characteristics, and a method for producing it. The anisotropic rare earth sintered magnet has a composition of a formula (R.sub.1-aZr.sub.a).sub.v(Fe.sub.1-bCo.sub.b).sub.100-v-w-x-y(M.sup.1.sub.1-cM.sup.2.sub.c).sub.wO.sub.xC.sub.y (where R is one or more kinds selected from rare earth elements and indispensably includes Sm, M.sup.1 is one or more kinds of elements selected from the group consisting of V, Cr, Mn, Ni, Cu, Zn, Ga, Al, and Si, M.sup.2 is one or more kinds of elements selected from the group consisting of Ti, Nb, Mo, Hf, Ta, and W, and v, w, x, y, a, b, and c each satisfy 7≤v≤15 at %, 4≤w≤20 at %, 0.2≤x≤4 at %, 0.2≤y≤2 at %, 0≤a≤0.2, 0≤b≤0.5, and 0≤c≤0.9), which contains a main phase of a ThMn.sub.12-type crystal compound in an amount of 80% by volume or more with the average crystal particle diameter of the main phase being 1 μm or more, which contains an R oxycarbide in the grain boundary area, and which has a density of 7.3 g/cm.sup.3 or more. The production method for the anisotropic rare earth sintered magnet includes grinding an alloy that contains a ThMn.sub.12-type crystal compound phase but does not contain an oxycarbide, then molding it in a mode of pressure powder molding with magnetic field application thereto to give a molded article, and thereafter sintering it at a temperature of 800° C. or higher and 1400° C. or lower to form an oxycarbide in the grain boundary area.

An anisotropic rare earth sintered magnet represented by the formula (R.sub.1-aZr.sub.a).sub.x(Fe.sub.1-b CO.sub.b).sub.100-x-y(M.sup.1.sub.1-cM.sup.2.sub.c).sub.y where R is at least one element selected from rare earth elements and Sm is essential; M.sup.1 is at least one of V, Cr, Mn, Ni, Cu, Zn, Ga, Al, and Si; M.sup.2 is at least one of Ti, Nb, Mo, Hf, Ta, and W; and x, y, a, b, and c each satisfy certain conditions. The anisotropic rare earth sintered magnet includes 80% by volume or more of a main phase composed of a compound of a ThMn.sub.12 type crystal, the main phase having an average crystal grain size of 1 μm or more, and containing an R-rich phase and an R(Fe,Co).sub.2 phase in a grain boundary portion. A method for producing the anisotropic rare earth sintered magnet is also described.

Provided are a method of producing a titanium-containing rare earth-iron-nitrogen anisotropic magnetic powder having good magnetic properties, and secondary particles for a titanium-containing anisotropic magnetic powder. The method includes: obtaining a first precipitate containing R, iron, and titanium by mixing a first precipitating agent with a solution containing R, iron, and titanium, wherein R is at least one selected from Sc, Y, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, and Lu; obtaining a second precipitate containing R and iron by mixing, in the presence of the first precipitate, a second precipitating agent with a solution containing R and iron; obtaining an oxide containing R, iron, and titanium by calcining the second precipitate; obtaining a partial oxide by heat treating the oxide in a reducing gas atmosphere; obtaining alloy particles by reducing the partial oxide; and obtaining an anisotropic magnetic powder by nitriding the alloy particles.

Provided are a method of producing a titanium-containing rare earth-iron-nitrogen anisotropic magnetic powder having good magnetic properties, and secondary particles for a titanium-containing anisotropic magnetic powder. The method includes: obtaining a first precipitate containing R, iron, and titanium by mixing a first precipitating agent with a solution containing R, iron, and titanium, wherein R is at least one selected from Sc, Y, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, and Lu; obtaining a second precipitate containing R and iron by mixing, in the presence of the first precipitate, a second precipitating agent with a solution containing R and iron; obtaining an oxide containing R, iron, and titanium by calcining the second precipitate; obtaining a partial oxide by heat treating the oxide in a reducing gas atmosphere; obtaining alloy particles by reducing the partial oxide; and obtaining an anisotropic magnetic powder by nitriding the alloy particles.

A permanent magnet including R and T. R are rare earth elements including Sm and at least one selected from Y and Gd. T is Fe alone or Fe and Co. T maybe partly substituted with M, and M is one or more selected from Ti, V, Cr, Mo, W, Zr, Hf, Nb, Ta, Al, Si, Cu, Zn, Ga and Ge. In a total content of R, Sm content is 60 at % or more and 95 at % or less, and a total content of Y and Gd is 5 at % or more and 35 at % or less. The permanent magnet includes main phase crystal grains having a ThMn.sub.12 type crystal structure.

Provided are a method of producing a titanium-containing rare earth-iron-nitrogen anisotropic magnetic powder having good magnetic properties, and secondary particles for a titanium-containing anisotropic magnetic powder. The method includes: obtaining a first precipitate containing R, iron, and titanium by mixing a first precipitating agent with a solution containing R, iron, and titanium, wherein R is at least one selected from Sc, Y, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, and Lu; obtaining a second precipitate containing R and iron by mixing, in the presence of the first precipitate, a second precipitating agent with a solution containing R and iron; obtaining an oxide containing R, iron, and titanium by calcining the second precipitate; obtaining a partial oxide by heat treating the oxide in a reducing gas atmosphere; obtaining alloy particles by reducing the partial oxide; and obtaining an anisotropic magnetic powder by nitriding the alloy particles.

A magnetic powder and a method for fabricating the same according to an embodiment of the present disclosure are provided. The magnetic powder is powder particles synthesized using a mixture of a rare earth oxide, a raw material, a metal, a metal oxide and a reducing agent, wherein the powder particles are single-phase, the raw material includes at least one of Fe and Co, the metal includes at least one of Ti, Zr, Mn, Mo, V and Si, and the metal oxide includes at least one of MnO.sub.2, MoO.sub.3, V.sub.2O.sub.5, SiO.sub.2, ZrO.sub.2 and TiO.sub.2.

Interstitially modified compounds of rare earth element-containing, iron-rich compounds may be synthesized with a ThMn.sub.12 tetragonal crystal structure such that the compounds have useful permanent magnet properties. It is difficult to consolidate particles of the compounds into a bulk shape without altering the composition and magnetic properties of the metastable material. A combination of thermal analysis and crystal structure analysis of each compound may be used to establish heating and consolidation parameters for sintering of the particles into useful magnet shapes.

A magnetic compound represented by the formula (R.sup.1.sub.(1-x)R.sup.2.sub.x).sub.a(Fe.sub.(1-y)Co.sub.y).sub.bT.sub.cM.sub.d wherein R.sup.1 is one or more elements selected from the group consisting of Sm, Pm, Er, Tm and Yb, R.sup.2 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, 0x0.7, 0y0.7, 4a20, b=100-a-c-d, 0<c<7.7, and 0d3, the magnetic compound having a ThMn.sub.12-type crystal structure, wherein the volume fraction of -(Fe, Co) phase is less than 12.3%.

A magnetic material is expressed by a composition formula: (R.sub.1-xZ.sub.x).sub.aM.sub.bT.sub.c, and includes a main phase having a ThMn.sub.12 crystal structure. In the ThMn.sub.12 crystal structure, when an amount of the element Z occupying 2a site is Z.sub.2a atomic percent, an amount of the element Z occupying 8i site is Z.sub.8i atomic percent, an amount of the element Z occupying 8j site is Z.sub.8j atomic percent, and an amount of the element Z occupying 8f site is Z.sub.8f atomic percent, Z.sub.2a, Z.sub.8i, Z.sub.8j, and Z.sub.8f satisfy (Z.sub.8i+Z.sub.8j+Z.sub.8f)/(Z.sub.2a+Z.sub.8i+Z.sub.8j+Z.sub.8f)<0.1.