Ni doped ZnO (Zn1-xNixO) thin films were grown on quartz substrates via magnetron sputtering deposition process with the Ni concentrations of 5, 10 and 20 at.% in the films. The effects of Ni doping level and post annealing on the structural and magnetic properties of Zn1-xNixO films were investigated by means of X-ray diffraction (XRD), alternating gradient magnetometer (AGM) and photoluminescence (PL). A higher magnetic moment was acquired from the annealed Zn1-xNixO film doped with 5 at.% Ni, which was attributed to a better preferred orientation from a primary phase Ni2+:ZnO in the film. A relatively more pronounced ZnO(002) peak observed from the Zni(1-x)Ni(x)O film doped with 5 at.% Ni indicated a good crystallinity of the film, which was attributed to a lower level of Ni content in the film as well as the Ni2+ ions substituted for the Zn2+ ions to form Ni2+:ZnO. A slight shift in ZnO(002) peak position for the 5 and 10 at.% Ni doped ZnO films could be due to the distortion of the ZnO lattice caused by the Ni2+ ion substituents for the Zn2+ ions. (c) 2007 Elsevier B.V. All rights reserved.