Artículos de revistas
Photochromic properties of tungstate-based glasses
Fecha
2007-05-15Registro en:
Solid State Ionics. Amsterdam: Elsevier B.V., v. 178, n. 11-12, p. 871-875, 2007.
0167-2738
10.1016/j.ssi.2007.01.012
WOS:000247230600019
2998503841917815
6446047463034654
3349586880746735
0000-0003-3286-9440
Autor
Universidade Federal de Alfenas (UNIFAL)
Universidade Estadual de Campinas (UNICAMP)
Universidade Estadual Paulista (Unesp)
Institución
Resumen
Vitreous samples were prepared in the NaPO(3)-BaF(2)WO(3) ternary system with high WO(3) concentrations. These glasses exhibit a strong absorption in the visible due to the presence of reduced tungsten species and the use of oxidizing species is required. The couple Sb(2)O(3)/NaNO(3) was introduced in the composition and allowed to obtain transparent glasses. These oxidized samples were illuminated by visible laser radiation and showed an efficient volumetric photochromic effect. The photosensitive effect appeared as a dark spot throughout the entire volume of the glasses. The effect was investigated by several techniques such as, U-V-visible absorption, Raman and XANES at the L(1) and L(3) tungsten absorption edges. The results suggest a photoreduction of tungsten atoms without structural changes of the viteous network. Finally, the photochromic effect can be erased by thermal treatment at 200 degrees C for a few minutes. (C) 2007 Published by Elsevier B.V.