Temperature Variation of the Elastic Constants of AgBr

By use of an ultrasonic pulse technique the elastic constants of AgBr have been measured between room temperature and the melting point. Resonance techniques have also been used to measure $S_{11}$ in the same temperature range. The results of the two different methods are the same within the limits of error. It is found that $C_{44}$ decreases only slightly with increasing temperature; $C_{11}$ and $C_{12}$, however, show a marked decrease, being reduced from their room temperature values by more than a factor of two at 400°C.