Artículos de revistas
Synthesis, Characterization, Anisotropic Growth and Photoluminescence of BaWO4
Fecha
2009-02-01Registro en:
Crystal Growth & Design. Washington: Amer Chemical Soc, v. 9, n. 2, p. 1002-1012, 2009.
1528-7483
10.1021/cg800817x
WOS:000263048200056
Autor
Universidade Federal de São Carlos (UFSCar)
Universidade Estadual Paulista (Unesp)
Institución
Resumen
This paper reports on the synthesis of barium tungstate (BaWO4) powders obtained by the coprecipitation method and processed in a domestic microwave-hydrothermal (MH) at 413 K for different times. These powders were analyzed by X-ray diffraction (XRD), Fourier transform Raman (FT-Raman) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy and fieldemission gun scanning electron microscopy (FEG-SEM). XRD patterns showed that the BaWO4 powders present a scheelite-type tetragonal structure and free of secondary phases. FT-Raman spectra proved the evidence of a tetragonal structure due to W-O stretching vibration into the [WO4] tetrahedron groups. FT-IR spectra revealed a strong shoulder on the nu(3) bands in the transmittance spectra of the powders. FEG-SEM micrographs indicated that the powders present an octahedron-like morphology with agglomerated nature and polydisperse particle size distribution. The morphological evolution of BaWO4 powders with the processing time in a MH system was investigated and a possible growth mechanism was proposed. A green photoluminescence (PL) emission at room temperature was verified for the BaWO4 powders when exited by 488 nm wavelength. Finally, a model was proposed to explain this physical property.