Mossbauer and XANES of TeO2-BaO-TiO2 glasses

Structure of TeO2-BaO-TiO2 glasses was studied by X-ray absorption spectros copy (XAS) at the Te L-III edge and Te-125 Mossbauer. A tight binding calcu lation was used to analyze the electronic structure of the crystalline mate rials. We show that the Te-125 Mossbauer isomer shift and the pre-peak surf ace of X-ray absorption spectra at the Te L-III edge are correlated. The li near dependence between these parameters demonstrates the complementarity b etween XAS and Mossbauer spectroscopy to analyze the Te(Ss) contribution to the structure. This variation is correlated to the coordination evolution of the tellurium atoms (TeO4 trigonal bipyramids to TeO3 trigonal pyramids) with the addition of modifier. (C) 1999 Elsevier Science B.V. All rights r eserved.