Ceramics-Silikáty 53 (1) 55-58 (2009)

Configurational entropy of selected zirconia containing silicate glasses

R. Karell, M. Liška, M. Chromčíková

The parameters of Adam - Gibbs equation (AG) were estimated for 28 glasses from the 15(K₂O, Na₂O)•10(ZnO, CaO)•75(ZrO₂, SiO₂) system. Configurational entropy at glass transition temperature, S^conf(T_g), and the B_AG parameter of AG equation were expressed as linear functions of the glass composition given in molar fractions of oxides. The same value of the A_AG parameter was used for all studied systems. The resulting AG equation described the experimental viscosity values with acceptable accuracy in the high temperature region. The obtained compositional trend of S^conf(T_g) corresponds well with the structural function of particular oxides.

Keywords: Configurational entropy, Adam - Gibbs equation