Rare earth-iron-nitrogen-based alloy powder

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PROBLEM TO BE SOLVED : To provide a rare-earth-iron-nitrogen based alloy powder which has superior coercivity (HcJ) and squareness (Hk), at a high yield and at a lower cost. SOLUTION : When producing a porous massive reaction product containing a rare-earth-iron based mother-alloy powder and a by-product by mixing a raw powder containing a rare-earth oxide powder and an iron powder with at least one reducing agent selected from an alkali metal, an alkaline earth metal and a hydride thereof, and reducing the rare-earth oxide powder to make a rare-earth element diffuse into an iron, this production method includes : using particles with particle sizes of 4.75 mm or less, in which 70 mass% or more particles have particle sizes of more than 0.5 mm but 2.5 mm or less, as the reducing agent; subsequently heat-treating the obtained porous massive reaction product in an atmosphere containing nitrogen to produce a nitrided rare-earth-iron based alloy powder; further removing the by-product from the alloy powder with wet treatment; and separating the rare-earth-iron-nitrogen based alloy powder. COPYRIGHT : (C)2010, JPO&INPIT