| 摘要 |
PURPOSE:To obtain the titled powder which is large in saturation magnetization and coercive force, excellent in corrosion resistance and useful as magnetic powder having high performance for a magnetic recording medium of a magnetic tape and a disk or the like by constituting the titled powder with iron nitride magnetic powder incorporated with Cr of specified quantity. CONSTITUTION:The titled powder which has 0.2-10atom% Cr, 18-30atom% N and the balance consisting of Fe with inevitable mixed impurities is obtained. The powder is made large in coercive force and saturation magnetization and excellent in corrosion resistance by containing the above-mentioned quantity of Cr to the iron nitride magnetic powder. The powder is obtained by reducing Cr- contg. Fe-based alloy powder or the powder of those metallic oxides or metallic oxyhydroxides under the atmosphere contg. H2, subjecting those powder to nitriding treatment at 250-700 deg.C under the atmosphere contg. ammonia and performing slow oxidation treatment (for example, those are oxidized in the inert atmosphere contg. 500-5,000ppm O2) after the nitriding treatment. |
