Ceramics-Silikáty 44 (3) 91-96 (2000)

THERMODYNAMIC PROPERTIES OF SODIUM-CONTAINING GLASSFORMING OXIDE MELTS

E. L. Kozhina, M. M. Shultz 

Electro-motive force investigation of Na₂O-R_aO_b (R = P, Si, B, Ge) and Na₂O-Q₂O₃-SiO₂ (Q = B, Al), as well as Na₂O-ZnO-P₂O₅ melts is carried out over a glassforming range. Temperature range under study varies within the limits 800 - 1400 K depending on the system under consideration. A complete set of thermodynamic properties, both partial and integral, is calculated being referred to the corresponding properties of the pure oxides. The results are discussed in terms of acid-base interaction in melt. Chemical structure of the melts is simulated from the ideal associated mixture model. On this basis an account for "germanate" and "borate anomalies" is proposed.