Effect of the pH pre-adjustment on the formation of In2W3O12 and In6WO12 powders: Cluster coordination and optical band gapEfecto del preajuste de pH en la formación de polvos In2W3O12 e In6WO12: coordinación de grupo y banda óptica
Abstract: In this communication, diindium tristungstate (In2W3O12) and hexaindium tungstate (In6WO12) powders were synthesized by the co-precipitation method at different pH values and heat treatment at 1073 K for 2 h. X-ray diffraction patterns and Rietveld refinements were employed to analyze the long-range structural ordering as well as quantify the presence crystallographic phases, respectively. All powders obtained in pH ranging from 2 to 3.5 exhibited a mixture of In2W3O12 and gamma-tungsten oxide (γ-WO3) phases. When prepared at pH close to 4, the powders presented both In2W3O12 and In6WO12 phases. All these crystalline structures were simulated in a three-dimensional visualization program by adopting the Rietveld refinements analysis as input data. The ultraviolet–visible spectra were employed to estimate the optical band gap energy of all powders for the first time.
Author(s): Paiva, R.T.; Nogueira, I.C.; Sczancoski, J.C.; Lemos, P.S.; Matos, J.M.E.; Santos, R.S.; Longo, E.; Cavalcante, L.S.
Boletín de la Sociedad Española de Cerámica y Vidrio
Publiched: January–February 2020, Volume 59, Issue 1, Pages 2-14
DOI: https://doi.org/10.1016/j.bsecv.2019.02.001
