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

A new preparation method for γ-Fe
2
O
3
thin film recording media has been established. Using sintered Fe
3
O
4
plates as targets, Fe
3
O
4
films 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-Fe
2
O
3
thin 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
-6dB
density as high as 1140 BPM (bits per millimeter).