Synthesis, growth process and photoluminescence properties of SrWO4 powders.

SrWO(4) powders were synthesized by the co-precipitation method and processed in a microwave-hydrothermal (MH) at 140 degrees C for different times. The obtained powders were analyzed by X-ray diffraction (XRD), micro-Raman (MR) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, field-emission gun scanning electron microscopy (FEG-SEM), ultraviolet-visible (UV-vis) absorption spectroscopy and photoluminescence (PL) measurements. XRD patterns and MR spectra showed that the SrWO(4) powders present a scheelite-type tetragonal structure without the presence of deleterious phases. FT-IR spectra exhibited a high absorption band situated at 831.57 cm(-1), which was ascribed to the WO antisymmetric stretching vibrations into the [WO(4)] tetrahedron groups. FEG-SEM micrographs suggested that the processing time is able to influence in the growth process and morphology of SrWO(4) powders. UV-vis absorption spectra revealed different optical band gap values for these powders. A green PL emission at room temperature was verified in SrWO(4) powders when excited with 488 nm wavelength.