The mixed-alkali effect in alternating-current conductivity was investigated in 25R2O(Na2O,K2O)-xAl2O3-(75-x)SiO2 melts, where x was equal to 0, 5, 7.5 or 10mol%, at temperatures of 1000 to 1400C. The results for the molten state exhibited a typical mixed-alkali effect; similar to that seen below the transformation temperature. The results implied that the interaction between 2 different alkali ions was maintained in the molten state. However, the mixed-alkali effect increased as the Al2O3 content was increased (decreasing non-bridging O content). The results were explained in terms of the binding state of AlO4--R+ and -O--R+, on the basis of the conductivity behavior of alkali aluminosilicate melts.

K.D.Kim: Journal of the American Ceramic Society, 1996, 79[9], 2422-8