Raman Spectroscopy and Statistical Analysis of the Silicate Species and Group Connectivity in Cesium Silicate Glass Forming System

The Raman spectra of %Cs2O-(100 − x)%SiO2 (, 22, 27, 33, and 37 mol%) glasses and melts were measured in the temperature range of 293 to 1553 K. The concentrations of the species were calculated as a function of the composition and temperature based on the deconvolution analysis of the spectra. It was found that a dynamic equilibrium among structural units in the melts with mol% can be described by disproportionation reaction . The enthalpy of this reaction was found to be equal to 32 ± 6, 43 ± 8, 56 ± 10, and 52 ± 9 for , 27, 33, and 37 mol%, respectively. The nonideal entropy of mixing (Δ) depends on the melt temperature and increases almost linearly with increasing temperature. The , , and distributions with ranging from 0 to 55 mol% were modeled using experimental data for the concentrations of the units.