The characteristics of abrupt change on elastic constants C33 of LiKSO4 crystal at 60°C

Using the ultrasonic pulse echo overlap technique, we have measured the temperature dependence of the elastic constant C33 of LiKSO4 crystal. The abrupt change of C33 occurs at 60°C, and there is a large temperature hysteresis. On repeated experiments, this abrupt peak of C33 reduces successively. But after a certain time of "seasoning", it appears again.