Magnetic Property and Spatial Occupation of Co Dopants in Zn_0.98Co_0.02O Nanowires

Single phase Co-doped ZnO dilute magnetic semiconductor nanowire was synthesized by a chemical solution method and characterized by X-ray absorption fine structure (XAFS). The Co K -edge XAFS spectroscopy reveals that the doped Co ions are substantially incorporated into the ZnO host lattice. Moreover, the spatial occupation of Co dopants in Zn 0.98 Co 0.02 O nanowire is resolved further by the detailed O K -edge XANES analysis. We suggest that the Co ions are randomly doped into the ZnO matrix and located at the Zn sites. The magnetization measurement of the Co-doped ZnO nanowire shows the room temperature ferromagnetic characteristic with a relatively larger saturation magnetization. Furthermore, we suggest that the enhanced ferromagnetism can be ascribed to the coeffect of the size effect and the homogeneity of Co dopants for Zn 0.98 Co 0.02 O nanowire, which will make it useful in nanometer spintronic devices.