Anomalous Temperature Dependence of Ultrasonic Velocity in Potassium Silicate Glasses

林明瑞(M. J. Lin)

《Chinese Journal of Physics》 23卷4期 (1985/12) Pp. 235-244

並列摘要

The results of ultrasonic experiment on a series of K2 0．xSiO2 (x = 4 to 9.5) glass samples are presented. The glass density is conspicuously proportional to the contained molar percentage of potassium oxide. At temperatures above 210K, the ultrasonic velocity shows anomalous linear increase with temperature for some of the glasses, with low K2 0 concentrations. For those with K2 0 molar percentages exceeding about 18%, the ultrasonic velocities decrease with temperature, showing a tendency of approaching normal elastic properties of a dielectric crystal. The temperature coefficient of ultrasonic velocity change at high temperatures has an approximate linear dependence on the K2 0 mole %, and there is a strong linear relationship between the ultrasonic velocity and the K2 0 concentration. Possible explanations in terms of thermal fluctuations in the glass network structure are discussed.