Abstract
Ferromagnetic semiconductor EuO and GdxEu1-xO (0.01<x<0.05) thin films were prepared by a reactive deposition method in an ultra-high-vacuum deposition system. Aluminum capping and a combination of Ar treatment and CaF2 capping are effective for protecting sample films. Both oxygen-deficient and Gd-doped EuO films were examined as electron-doped ferromagnetic semiconductors. The Gd doping looks more promising due to the chemical stability and the better electron doping controllability.
