Rietveld refinement, morphology and optical properties of (Ba1-xSrx)MoO4 crystals

Author(s)

Nogueira, I. C. ; Cavalcante, L. S. ; Pereira, P. F. S. ; de Jesus, M. M. ; Rivas Mercury, J. M. ; Batista, N. C. ; Siu Li, M. ; Longo, E.

• Document type: Journal article
• Source: JOURNAL OF APPLIED CRYSTALLOGRAPHY; v. 46, p. 13-pg., 2013-10-01.

Abstract

In this article, the structural refinement, morphology and optical properties of barium strontium molybdate [(Ba1-xSrx)MoO4 with x = 0, 0.25, 0.50, 0.75 and 1] crystals, synthesized by the co-precipitation (drop-by-drop) method, are reported. The crystals obtained were structurally characterized by X-ray diffraction (XRD), Rietveld refinement, and Fourier transform-Raman (FT-Raman) and Fourier transform-infrared (FT-IR) spectroscopies. The shapes of the crystals were observed by means of field-emission scanning electron microscopy (FE-SEM). The optical properties were investigated using ultraviolet-visible (UV-Vis) absorption spectroscopy and photoluminescence (PL) measurements. XRD patterns, Rietveld refinement, and FT-Raman and FT-IR spectra showed that all of the crystals are monophasic with a scheelite-type tetragonal structure. The refined lattice parameters and atomic positions were employed to model the [BaO8], [SrO8] and [MoO4] clusters in the tetragonal lattices. The FE-SEM images indicate that increased x content produces a decrease in the crystal size and modifications in the crystal shape. UV-Vis spectra indicated a decrease in the optical band gap with an increase in x in the (Ba1-xSrx)MoO4 crystals. Finally, a decrease in the intensity of PL emission is apparent with an increase in x up to 0.75 in the (Ba1xSrx)MoO4 crystal lattice when excited by a wavelength of 350 nm, probably associated with the degree of structural order-disorder. (AU)

• FAPESP's process: 09/50303-4 - Optical and photocatalytic properties of ZnMoO4 and ZnWO4
• Grantee: Laécio Santos Cavalcante
• Support Opportunities: Scholarships in Brazil - Post-Doctoral