| 摘要 |
PURPOSE:To attain high textural closeness of a deposited film and to improve the stability of oxidation by electroless-plating metal magnetic powder in a medium liquid which contains a specific metal ion and by annealing the treated metal magnetic powder under specific conditions. CONSTITUTION:A metal compound aqueous solution which contains at least one kind of metal ion selected from a group of nickel, cobalt, copper, gold, silver and palladium is added with various buffers and complexing agents as required and a plating bath is adjusted by desirably adding a reducing agent. Ferrous metal particle powder of iron or various ferrous alloys whose main component is iron is dipped in the plating bath and metal ions are separated out on the surface of the particle in the form of a metal film by stirring for a definite time. Then, magnetic powder recovered by separating a bath liquid is treated by heat at normally within 200-500 deg.C under the flow of such as an argon gas. Then, the metal magnetic powder which is appropriate for a high density magnetic recording medium and improved in the stability of oxidation is obtained. |
