| 摘要 |
PURPOSE:To obtain a gamma-Fe2O3 thin film excelent in magnetic properties formed directly on a substrate, by employing a target having Fe3O4 as its main component, and effecting sputtering in the atmosphere of an inert gas having a specific O2 content. CONSTITUTION:As a target, Fe3O4 or Fe3O4 having CO, Cu, Ni or the like added thereto is emplyed, and sputtering is effected in the atmosphere of a mixed gas of CO2, N2, Ar or the like containing 0.05-5vol% O2. As a result, a gamma-Fe3O4 thin film excellent in magnetic properties is formed directly on a substrate. Moreover, since the temperature of the substrate will not exceed 100 deg.C during the sputtering, it is possible to employ as the substrate a plastic in addition to Al and an Al-base alloy. It is to be noted that an O2 content less than 0.05vol% allows Fe3O4 to be included in the thin film, while an O2 content exceeding 5vol% allows alpha-Fe2O3 in non-magnetic phase to be included in gamma- Fe2O3, both resulting in deteriorations in magnetic recording properties. |
