Ferromagnetism in chromium-doped reduced-rutile titanium dioxide thin films

Cr-doped reduced-rutile TiO2 thin films were grown on R-plane sapphire substrates by pulsed-laser deposition. X-ray diffraction and transmission electron microscopy results indicate that the films are single phase and reduced-rutile type. Superconducting quantum interference device magnetometer measurements show the films are ferromagnetic up to 400 K. A large magnetic moment of 2.9 μB per Cr atom is found for 6% Cr-doped reduced films at room temperature, and the saturation magnetization of the films decreases with increasing Cr doping. The temperature dependence of the resistivity shows semiconducting behavior.