Synthesis, characterisation and photoluminescence of nanocrystalline calcium tungstate

摘要

Calcium tungstate nanocrystalline was successfully synthesised via a microwave irradiation method using Ca(NO_3)_2 and Na_2WO_4 in ethylene glycol, without the requirement of any calcination. The product was analysed by X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and photoluminescence spectrometry. XRD, SAED and TEM revealed that the product was body-centred tetragonal CaWO4 with an average particle size of 12 nm. Different oscillation modes were detected by Raman spectroscopy and FTIR. They showed the strong W-O stretching in [WO_4]~(2-) tetrahedrons at 711-933 cm~(-1). Photoluminescence (PL) of CaWO_4 nanocrystalline showed the maximum emission peak at 422 nm.