title: Synthesis, growth process and photoluminescence properties of SrWO4 powders.
abstract: 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.
authors.affiliation: LIEC, Universidade Federal de São Carlos, Departamento de Química e Física, São Carlos, P.O. Box 676, 13565-905, SP, Brazil.
authors.forename: J C
authors.initials: JC
authors.lastname: Sczancoski
authors.forename: L S
authors.initials: LS
authors.lastname: Cavalcante
authors.forename: M R
authors.initials: MR
authors.lastname: Joya
authors.forename: J W M
authors.initials: JW
authors.lastname: Espinosa
authors.forename: P S
authors.initials: PS
authors.lastname: Pizani
authors.forename: J A
authors.initials: JA
authors.lastname: Varela
authors.forename: E
authors.initials: E
authors.lastname: Longo