Dynamics and crystal chemistry of tellurites: 1. Raman spectra of thallium tellurites: Tl2TeO3, Tl2Te2O5 and Tl2Te3O7 Original Research Article

Raman spectra of the three entitled crystals are analysed within the framework of a lattice-dynamical model treatment using preliminary obtained X-ray diffraction data. The short range atomic arrangement and spectrochemical peculiarities of these structures are jointly discussed, which is considered as an initial step for studying the nature of the glass phases in the xTl2O+(1−x)TeO2 system. The charged TeO32− groups and the neutral TeO2 quasi-molecules are proposed as the basic units forming the complex tellurite anions. However, no relevant characteristic frequencies can be indicated in the spectra since the interatomic separation in those units are highly variables and their vibrational states are mixed and delocalised.