| 摘要 |
PURPOSE:To enable oxidation resistance and magnetic property to be improved by forming a needle-shaped iron particle powder by reducing a needle-shaped gate particle, forming Fe4N by performing nitriding treatment of this powder, and coating the powder where this Fe4N is formed on a substrate. CONSTITUTION:An iron powder is inserted into a reaction container, inside of the container is heated to for example approximately 500 deg.C by an external heater, and nitriding treatment is performed while feeding NH3 gas, H2 gas, etc., from a lower part of the container and the iron powder allowed to float and flow. In this case, nitriding conditions are properly set so that the generated nitriding iron positively consists of Fe4N. Therefore, by performing nitriding treatment, flocculation of a powder particle can be avoided and a needle-shaped particle shape can be maintained. Therefore, Fe4N where the needle-shaped particle could not be maintained by flocculation at the time of nitriding treatment before can be applied to a magnetic recording medium, thus obtaining a magnetic recording medium which is superb in oxidation resistance and improved magnetic characteristics. |
