Room-temperature ferromagnetism in manganese doped reduced rutile titanium dioxide thin films

MnxTi1-xO2-delta (x=0.02-0.12) thin films grown on alpha-Al2O3 substrates by pulsed-laser deposition have been investigated. 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 at room temperature with nonzero coercivity up to 170 Oe. The saturation magnetization of the reduced films is as high as 0.83 mu(B) per Mn atom at room temperature. The temperature dependence of the resistivity shows semiconducting behavior with p-type carriers. The nature of the p-type conduction and its significance to the ferromagnetism are discussed. (C) 2004 American Institute of Physics.