Magnetic Anisotropy of Ni-Doped ZnO Nanocrystalline Thin Films

We report structural and magnetization properties of nickel-doped zinc oxide thin films prepared on Si substrates by spray pyrolysis technique. Grazing angle X-ray diffraction measurements confirm the wurtzite structure of Zn1-xNixO films and no secondary phase was found for ZnO thin films doped with 5% Ni or less. Hysteresis measurements demonstrate that the Ni-doped ZnO films are magnetically anisotropic and they exhibit intrinsic ferromagnetic behavior at room temperature. Higher magnetization in 3kOe is observed for a field applied perpendicular to the sample surface compared with the in-plane direction. (C) 2010 The Japan Society of Applied Physics