Effect of Zn2+ ions on the structure, morphology and optical properties of CaWO4 microcrystals

Journal of Sol-Gel Science and Technology Volume: 72 Issue: 3 Pages: 648-654 Published: 2014

18 de novembro de 2014 Rose Portasio Artigo 0

Proposed-growth-and-formation-mechanisms-for-the — Proposed growth and formation mechanisms for the (Ca1-xZnx)WO4 microcrystals with Zn2+ concentrations: a electrostatic attraction of Ca2+/Zn2+ and WO2- 4 ions in solution and possible interactions, b aggregation process for small nuclei, c small crystals grow by self-assemble process due to specific conditions of the chemical reaction and d final stage of crystals growth of dumbbell-, cocoa-, custard apple-, decorative ball-like microcrystals.

Writers: Márcio A. P. Almeida, J. R. O. Lima, C. Morila-Santos, Paulo N. Lisboa Filho, M. Siu Li, Elson Longo, Laécio S. Cavalcante

Keywords: CaWO4; Microcrystal; Zinc; Distortions; Photoluminescence

Abstract: The effect of zinc ions (Zn2+) on the structure, morphology and optical properties of (Ca1-xZnx)WO4 microcrystals with (x = 0, 0.01, 0.02, and 0.03) obtained by the microwave-hydrothermal method at 170 C for 1 h is reported in this letter. These microcrystals were characterized by X-ray diffraction (XRD), Rietveld refinement, energy dispersive X-rays spectroscopy (EDXS) and field emission scanning electron microscopy (FE-SEM) images. The optical properties were investigated by ultraviolet–visible (UV–Vis) diffuse reflectance spectroscopy and photoluminescence (PL) measurements. XRD patterns and Rietveld refinement data.