Structural peculiarities and Raman spectra of TeO2/WO3-based glasses: A fresh look at the problem

Ideas currently dominating the field of structural studies of TeO2-based glasses are critically considered. A new physically and chemically consistent approach to the constitution of binary TeO2–WO3 glasses is proposed, in which the reasoning coming from the Raman spectra reexamination are correlated with the basic principles of thermodynamics. Separation into two phases is suggested in such glasses. One phase is TeO2, and another is Te(WO4)2 consisting of tetrahedral [WO4]2− anions and of Te4+ cations. Supplementary MnOk oxides added to the glasses are found incorporated in the former phase, thus producing solid solutions (for M=Ti, Nb) or tellurite compounds (for M=Nd).