Influence of annealing temperature on structural, optical and magnetic properties of Zn_0.97Cu_0.01V_0.02O nanoparticles

Zn_0.97Cu_0.01V_0.02O nanoparticles have been successfully prepared by the sol–gel method and sintered in air at the different temperature. The effects of the annealing temperature on the structural, optical and magnetic properties of the obtained samples were studied. The X-ray diffraction (XRD) results showed that the Zn_0.97Cu_0.01V_0.02O nanoparticles was single phase with the ZnO-like wurtzite structure when the annealing temperature was <700 °C. The photoluminescence (PL) spectra revealed that as the annealing temperature increased, the intensity of the UV emission increased and the green emission enhanced significantly. Magnetic measurements indicated that the samples exhibited ferromagnetism at the room temperature. The results of XRD, transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS) revealed that there was no ferromagnetic-related secondary phase in Zn_0.97Cu_0.01V_0.02O nanoparticles, the ferromagnetism of the Zn_0.97Cu_0.01V_0.02O samples was originated from the fact that the Cu and V ions doped into the ZnO lattice. In addition, the saturation magnetization (Ms) increased with the enhancement of the annealing temperature.