A new preparation method for γ-Fe2O3thin film recording media through direct sputtering of Fe3O4thin films

A new preparation method for γ-Fe2O3thin film recording media has been established. Using sintered Fe3O4plates as targets, Fe3O4films are directly formed over wide sputtering condition ranges through R.F. sputtering in argon atmosphere. Planar magnetron sputtering has successfully been attempted to attain sputtering rates higher than 2,000 Å/min. Co, Cu doped γ-Fe2O3thin film disks have been prepared by the present method. Their read/write characteristics were experimentally evaluated using a conventional ferrite head with 20 μm core width, which has shown D-6dBdensity as high as 1140 BPM (bits per millimeter).