Micro-structural investigations and paramagnetic susceptibilities of zinc oxide, europium oxide and their nanocomposite

Abstract

Nanoparticles of zinc oxide (ZnO), europium oxide (Eu 2O 3) and their nanocomposite system {(ZnO) 0.55(Eu 2O 3) 0.45} have been prepared by pyrophoric reaction and chemical co-precipitation methods. The precursor materials used for the synthesis were Zn(NO 3) 2·6H 2O and bulk Eu 2O 3. For nanocrystallization, the as-prepared samples were annealed at 500 and 600 °C for 6 h. The X-ray diffractograms (XRD) confirmed the formation of desired phases of the nanoparticles of ZnO, Eu 2O 3 and nanocomposite of {(ZnO) 0.55 (Eu 2O 3) 0.45}. Particle sizes of all the samples have been estimated from the width of the XRD peaks using the Debye–Scherrer equation. Particle sizes, crystallographic phases, etc. extracted from the high resolution transmission electron microscopy of a few selected samples are in agreement with those obtained from the XRD. Field emission scanning electron microscopy showed that ZnO nanoparticles are more-or-less spherical in shape. Average magnetic susceptibilities of all the annealed samples measured in the temperature range of 300–14 K indicate that all the samples including the zinc oxide, which is normally diamagnetic in the bulk state, are paramagnetic and the data are tried to analyze by the Curie–Weiss law. Photo-luminescence data recorded at room temperature of all the samples indicate that the optical property of the ZnO nanoparticles are not affected by Eu 2O 3 nanoparticles in the nanocomposite system though its bulk magnetization is substantially enhanced by incorporating the Eu 2O 3 nanoparticles.