| 摘要 |
PURPOSE:To improve magnetic characteristics such as square ratio and orientability by a method wherein at least one of metal compounds of Cs, Ni, Ce and the like is contained in magnetic ferrous oxide powder at the specific step of the manufacturing process of magnetic ferrous oxide powder containing cobalt. CONSTITUTION:Magnetic ferrous oxide powder is dispersed in an alkaline solution such as sodium hydroxide and a ferrous salt such as a ferrous sulfate is added. Then a cobalt salt such as cobalt sulfate is added to the solution. Or the magnetic ferrous oxide powder is dispersed in a solution containing a ferrous salt and an alkaline solution is added and then a cobalt salt is added. In this process, at least one of metal compounds of Cs, Ni, Ce and the like is contained in the magnetic ferrous oxide powder after the application of the compound which is applied at the former step and before the application of the compound which is applied at the latter step for the compound applied at the former step and at the time of its application for the compound applied at the latter step. |
