Abstract
Thin (Fe,Co,Mn)3O4 films were deposited in-situ on Si substrate under well controlled O2 partial pressure by dc-reactive magnetron sputtering. The coercivity of as-deposited magnetite films is around 400 ~ 640 Oe. After oxidation at 360°C for 90 minutes, the films transform to maghemite γ-(Co,Mn,Fe)2O3 completely, and the coercivity is increased 1 ~ 7 times to 640 ~ 3500 Oe, depending on the target composition. The origin of coercivity enhancement is attributed to magneto-anisotropy which is induced by the interfacial stress of the films and directional order brought by Co and Mn. © 1995 IEEE