| 摘要 |
PURPOSE:To improve the erasing characteristics of the magnetic recording medium as well as to increase the output by forming an iron oxide layer including cobalt on the surface of particles of the magnetic powder by dispersing the magnetic powder of iron oxide in alkali solution and further adding solution of cobalt salt and ferrous salt into said solution. CONSTITUTION:When magnetic powder of iron oxide is treated in the solution including cobalt salt and ferrous salt to form an iron oxide layer including cobalt on the surface of particles of the magnetic powder, the magnetic powder of iron oxide is dispersed in alkali solution. Next, into said alkali solution, the solution of cobalt salt and ferrous salt is added while dividing it into at least two adding segments. Also, the amount of the cobalt salt solution for each addition is determined in a manner that the content of cobalt in the produced magnetic powder is within a range 0.5-2.0wt%. Thus the erasing characteristics of the magnetic recording medium is improved and the output of the medium is contrived to be increased. |
