Magnetic and optical properties of znO nanowire arrays synthesized by a simple hydrothermal process

In this paper, vertically aligned ZnO nanowire arrays were synthesized by a simple hydrothermal process. The microstructure, morphology, magnetic and optical properties of the as-prepared samples were characterized by x-ray diffraction (XRD), scanning electron microscope (SEM), vibrating sample magnetometer(VSM) and photoluminescence spectrum (PL). The results show that the vertically aligned ZnO nanowire arrays are hexagonal wurtzite structures with the high (002)-orientation. At room temperature, all the samples possess ferromagnetism with the saturation magnetic moment of 0.1443 emu/g. The PL measurements illustrate that the as-prepared ZnO nanowire arrays exhibit a strong yellow-green emission centered at about 550 nm and a weak near-ultraviolet (UV) emission at about 375nm. A possible origin of ferromagnetism and yellow-green emission of the ZnO nanowire arrays related to the intrinsic defect is proposed.