Fe3O4膜直接形成によるγ-Fe2O3薄膜記録媒体の新作製法
1981 年 5 巻 2 号 p. 141-144
詳細
1981 年 5 巻 2 号 p. 141-144
A new preparation method for γ-Fe2O3 thin film recording media has been established.
Using sintered Fe3O4 plates as targets, magnetic film are directly formed through ordinary r. f. sputtering in argon atmosphere. Those as-sputtered film compositions were examined and confirmed to be Fe3O4, which were formed over wide sputtering condition range.
In order to realize high-rate sputtering, planar magnetron r. f. sputtering was attempted. Sputtering rates several times higher than those for ordinary sputtering were obtained. A rate as high as 2, 000 Å/min was attained at high power densities. These as-sputtered films were also confirmed to be Fe3O4 and formed over wide ranges of argon pressure 2×10-3-5×10-2 Torr, substrate temperature; R. T.-300°C, and target-substrate distance 2-4cm. Thus, the present method assures high productivity and reproducibility.
Effects of other elements doping have been investigated to improve Fe3O4 film properties. As doping elements, cobalt and copper were chosen. Copper promoted oxidation from Fe3O4 to γ-Fe2O3. It was revealed that γ-Fe2O3 films (ρ=1×103Ω·cm) on anodized aluminum alloy substrates, obtained by high-rate sputtering of 2% Co, 2% Cu doped Fe3O4 target, had magnetic characteristics suitable for high recording densities.
