Sm-Fe-N BASED MAGNETIC PARTICLE POWDER FOR BONDED MAGNET AND ITS MANUFACTURING METHOD, RESIN COMPOSITION FOR BONDED MAGNET, AND BONDED MAGNET

摘要

PROBLEM TO BE SOLVED: To provide Sm-Fe-N based magnetic particle powder which is excellent in a particle size distribution and has small magnetic distribution as well as excellent weather-resistance without any special treatment on the particle surfaces, and to provide a method of manufacturing the magnetic particle powder and a bonded magnet composition using it and a bonded magnet.;SOLUTION: The Sm-Fe-N based magnetic particle powder which shows a slope in the atomic ratio of Sm/Fe from the particle surface to the center is obtained as follows; after aqueous solution including samarium is added to water suspension including iron oxide particles, the pH of the suspension is adjusted to 8.0 to 14.0 and heated to 50 to 100°C to coat the surfaces of the oxide particles with the samarium compound, and thereafter reductive reaction is conducted to the oxide iron particles coated with the samarium compound. After the reductive reaction, metal Ca is added to the powder and reductive diffusion reaction is conducted under an inactive gas atmosphere to form Sm-Fe alloy particles. Nitriding reaction is conducted to the Sm-Fe alloy particles after the reductive diffusion reaction.;COPYRIGHT: (C)2008,JPO&INPIT