Magnetic and Raman scattering studies of Co-doped ZnO thin films grown by pulsed laser deposition

摘要

Phase pure Zn_(1-x)Co_xO thin films grown by pulsed laser deposition have transmittance greater than 75 % in the visible region. Raman studies confirm the crystalline nature of Zn_(1-x)Co_xO thin films. Zn_(0.95)Co_(0.05)O thin films show room temperature ferromagnetism with saturation magnetization of 0.4μ_B/Co atom. The possible origin of paramagnetism at higher Co doping concentrations can be attributed to the increased nearest-neighbor antiferromag-netic interactions between Co~(2+) ions in ZnO matrix. XPS confirms the substitution of Co~(2+) ions into the ZnO host lattice.