An magnetic material is a magnetic material expressed by a composition formula: (R.sub.1-xY.sub.x).sub.aM.sub.bT.sub.cA.sub.d, which includes a main phase consisting of a ThMn.sub.12 type crystal phase. 30 atomic percent or more of the element M in the composition formula is Fe.

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%.

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.

New magnetic materials containing cerium, iron, and small additions of a third element are disclosed. These materials comprise compounds Ce(Fe.sub.12xM.sub.x) where x=1-4, having the ThMn.sub.12 tetragonal crystal structure (space group I4/mmm, #139). Compounds with M=B, Al, Si, P, S, Sc, Co, Ni, Zn, Ga, Ge, Zr, Nb, Hf, Ta, and W are identified theoretically, and one class of compounds based on M=Si has been synthesized. The Si cognates are characterized by large magnetic moments (4M.sub.s greater than 1.27 Tesla) and high Curie temperatures (264T.sub.c305 C.). The Ce(Fe.sub.12xM.sub.x) compound may contain one or more of Ti, V, Cr, and Mo in combination with an M element. Further enhancement in T.sub.c is obtained by nitriding the Ce compounds through heat treatment in N.sub.2 gas while retaining the ThMn.sub.12 tetragonal crystal structure; for example CeFe.sub.10Si.sub.2N.sub.1.29 has T.sub.c=426 C.

A SmFeN-based magnetic material in which the use amount of Sm is further reduced while enhancing the saturation magnetization, and a production method thereof, are provided. The present disclosure discloses a SmFeN-based magnetic material including a main phase having a crystal structure of at least either Th.sub.2Zn.sub.17 type or Th.sub.2Ni.sub.17 type, wherein the main phase is represented by the molar ratio formula (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 one or more rare earth elements other than Sm, La and Ce, and Zr, and M is one or more elements other than Fe, Co, Ni and rare earth elements, and an unavoidable impurity element, and 0.09x0.31, 0.24y0.60, 0.51x+y0.75, 0z0.10, 0p+q0.10, 0s0.10, and 2.9h3.1 are satisfied, and a production method thereof.

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 7v15 at %, 4w20 at %, 0.2x4 at %, 0.2y2 at %, 0a0.2, 0b0.5, and 0c0.9), 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 m 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.