HIGH COERCIVITY GAMMA-(FE,CO,MN)(2)O-3 THIN-FILMS FOR MAGNETIC RECORDING

Thin (Fe,Co,Mn)(3)O-4 films mere deposited in-situ on Si substrate und er well controlled O-2 partial pressure by de-reactive magnetron sputt ering. The coercivity of as-deposited magnetite films is around 400 si milar to 640 Oe. After oxidation at 360 degrees C for 90 minutes, the films transform to maghemite gamma-(Ca,Mn,Fe)(2)O-3 completely, and th e coercivity is increased 1 degrees 7 times to 640 similar to 3500 Oe, depending on the target composition. The origin of coercivity enhance ment is attributed to magneto-anisotropy which is induced by the inter facial stress of the films and directional order brought by Co and Mn.