Internal Friction in Alkali Aluminosilicate Glasses Containing Divalent Ions

Abstract

The internal friction of alkali aluminosilicate glasses containing divalent ions was measured from -100° to 550°C at a frequency of about 1Hz and two peaks were obseved. The peak observed at low temperature is due to the motion of alkali ions, i.e. the low temperature peak. Since the compositional dependence of the peak observed at high temperature was similar to that of the mixed-cation peak in mixed alkali glasses, it was suggested that its peak was the mixed-cation peak which was attributed to coexistence of alkali and divalent ions. The relaxation mechanism of the mixed-cation peak is probably associated with the interaction between alkali and divalent ions, and is essentially the same as that of the mixed-cation peak in mixed alkali glasses. There was the close correlation that the heights of the low-temperature peak and the mixed-cation peak were inversely proportional each other. Consequently, the relaxation mechanisms of the mixed-cation peak must have the same kind of relaxation element of the low-temperature peak, i.e. alkali ions.