Investigation of alumino-silicate glasses by coupling experiments and simulations: Part I - Structures

A set of alumino-silicate glasses with SiO2-Al2O3-Na2O-CaO compositions was investigated using Raman and NMR spectroscopy techniques by classical molecular dynamics, in order to study the structural modifications which occur when CaO progressively replaces Na2O Al2O3 SiO2. The effect a gradual increase content also studied. Al always 4 coordinated for all studied, including peraluminous glasses. An number Al-O-Al bonds found or increases. confirmed that AlO4 groupings are preferentially compensated Na rather than Ca, there non-bridging oxygens surrounded mixed environments containing both Ca. Combining information given results enabled attribution band at 570cm-1 Si-O-Al bonds. It 510cm-1 can be attributed bonds, while 985cm-1 Q4-Al entities. Lastly, it demonstrated dynamics potentials Deng et al., specifically developed this type glasses, permit reproduction large experimental quantitatively sometimes simply qualitatively.