| 摘要 |
PURPOSE:To obtain magnetic powder with cobalt applied uniformly on magnetic iron oxide by producing hydrolysis products of a cobalt salt through the heating of a hydrate solution containing an oxide magnetic material and a cobalt salt. CONSTITUTION:As a cobalt salt any one of cobalt acetate, cobalt surfate, cobalt nitrate, and the like is preferred, and is used as its water solution. gamma-Fe2O3 particles are input to cobalt water solution and are dispersed sufficiently by means of ultra-sonic wave bath. Nitrogen gas is input to them and bubbling is performed so that the amount of dissolved oxygen in the solution is reduced to 3ppm. They are sealed and their temperature is raised to 100<=, maintained for 24 hours, and lowered naturally. After this cooling, suspension is taken out of a container, filtered, and dried. Since hydrolysis products of the cobalt salt are made through heating process in this manner, the reaction is made while this reaction system is maintained in a uniform status. As a result, the deposition of cobalt salt can be made uniformly. |
