Rare earth magnet material and method for producing the same

Abstract

A method for producing a rare earth magnet material which allows efficient Dy or the like diffusion into an inside thereof. This method includes a preparation step of preparing a powder mixture of magnet powder including one or more rare earth elements including neodymium, boron, and the remainder being iron; and neodymium fluoride powder; a heating step of heating a compact of the powder mixture and causing oxygen around magnet powder particles to react with the fluoride powder, thereby obtaining a lump rare earth magnet material in which neodymium oxyfluoride is wholly distributed. The fluoride powder traps oxygen enclosed in the powder mixture and fixes the oxygen as stable NdOF. When Dy is diffused into this rare earth magnet material, Dy smoothly enters into its inside without being oxidized at grain boundaries. Consequently, coercivity of the entire rare earth magnet material can be efficiently increased without wasting scarce Dy.