Abstract: The process for producing a magnet according to the invention is characterized by comprising a first step in which a heavy rare earth compound containing Dy or Th as a heavy rare earth element is adhered onto a sintered compact of a rare earth magnet and a second step in which the heavy rare earth compound-adhered sintered compact is subjected to heat treatment, wherein the heavy rare earth compound is a Dy or Th iron compound.

Abstract: A method for producing a rare earth sintered magnet uses granules having an excellent fluidity to improve the dimensional accuracy and production of a compact formed of the granules without significant property losses. The granules are formed by adding an organic liquid to primary alloy particles having a predetermined composition to produce granules having the primary alloy particles adhered together by the organic liquid. Preferably, from 1.5 to 15.0% by weight of the organic liquid is added to the primary alloy particles.

Abstract: The present invention provides a Mn—Zn ferrite which is low in the loss in the frequency range between a few 10 kHz and a few 100 kHz and high in the saturation magnetic flux density in the vicinity of 100° C. The present invention comprising the steps of compacting a powder having a specific surface area (based on the BET method) of 2.0 to 5.0 m2/g and a 50% particle size of 0.7 to 2.0 ?m into a compacted body having a predetermined shape and obtaining a sintered body by sintering the compacted body. It is preferable that a Mn—Zn ferrite comprises, as main constituents, 54 to 57 mol % of Fe2O3, 5 to 10 mol % of ZnO, 4 mol % or less (not inclusive of 0%) of NiO, and the balance substantially being MnO.

Abstract: The present invention provides a Mn—Zn ferrite which is low in the loss in the frequency range between a few 10 kHz and a few 100 kHz and high in the saturation magnetic flux density in the vicinity of 100° C. The present invention comprising the steps of compacting a powder having a specific surface area (based on the BET method) of 2.0 to 5.0 m2/g and a 50% particle size of 0.7 to 2.0 ?m into a compacted body having a predetermined shape and obtaining a sintered body by sintering the compacted body. It is preferable that a Mn—Zn ferrite comprises, as main constituents, 54 to 57 mol % of Fe2O3, 5 to 10 mol % of ZnO, 4 mol % or less (not inclusive of 0%) of NiO, and the balance substantially being MnO.