Ferrite thin films for high recording density

Ferrite thin films with superior mechanical and magnetic properties for a magnetic disk medium have been obtained using reactive sputtering. Recording characteristics of these films considerably exceed those of a conventional γ-Fe2O3coating medium. Hematite thin films were produced on an aluminium alloy substrate by sputtering Fe-Al-Co alloy target in an atmosphere of mixed argon and oxygen. Hematite films were transformed to ferrite films by reduction in hydrogen atmosphere for 2-4 hours at 300°C. The substrate used was covered with a thin alumite layer formed by anodic oxidation to improve surface hardness.