Structural characterization of bulk ZnWO4 prepared by solid state method

Abstract

Uniform crystals of ZnWO₄ have been synthesised from the equimolar mixtures of ZnO and WO₃ by conventional solid state method. For the first time the sample has been characterised detailedly to confirm the formation of pure single phase of perovskite ZnWO₄. The formation of ZnWO₄ has been confirmed by sintering the mixtures of ZnO and WO₃ at two different temperatures one at 900 °C and other at 1000 °C. It is observed that the sample sintered at 1000 °C for 24 h shows complete formation of the single phase of ZnWO₄. The crystallinity and the phase formation has been confirmed by X-ray diffraction technique. X-ray photoelectron spectroscopy measurements have been carried out for the bulk ZnWO₄ sintered at 1000 °C for 24 h, showing 16% of Zn, 16% of W and 68% of O indicating stoichiometric ZnWO₄. Surface morphology studies by scanning electron microscopy showed uniform crystals of ZnWO₄. The purity of the compound has also been checked in depth by Energy Dispersive X-ray method indicating the absence of foreign ions apart from that, the ratio of Zn : W has been calculated and found to be 1 : 1 confirming the stoichiometric ZnWO₄ inside the crystals.