Quantitative Raman spectroscopy: speciation of cesium silicate glasses

The silicate speciation forms an important aspect of the structure of silicate melts, a subject of interest to both the earth‐ and materials science communities. In this study, the Q n speciation of binary cesium silicate glasses was studied by Raman spectroscopy. A method to extract the equilibrium constant from a set of Raman spectra is presented, and the least‐squares optimization algorithm is given (in Supporting Information). Log( K ), the equilibrium constant of the speciation reaction, 2Q 3 = Q 4 + Q 2 , equals −2.72 ± 0.11 at the glass transition. This extends the previously established correlation between log( K ) and the inverse of the ionic radius of the network modifier to cesium.