Thermal decomposition synthesis and magnetic properties of crystalline zinc oxide powders

Abstract

Crystalline zinc oxide powders are prepared by a direct thermal decomposition of zinc nitrate hexahydrate in air at 500 °C for 2 h. The thermal behavior of zinc precursor compound was studied using TG-DTA analysis in order to define the ZnO formation temperature. The structure of the calcined sample was characterized by X-ray diffraction (XRD). The XRD result indicates that the sample has a pure phase with ZnO wurzite structure. The morphology and elemental composition have been identified through SEM and EDX analyses. The oxidation state of ZnO sample was investigated using X-ray absorption near-edge spectroscopy (XANES). The ZnO sample reveals ferromagnetic behavior with the magnetization of ∼0.50 emu/g at 15 kOe. Our results indicate that room-temperature ferromagnetism of ZnO is intrinsic.