STUDIES OF THE ULTRASONlC PROPERTIES OF TRlGLYCINE SULFATE (TGS) SINGLE CRYSTAL

摘要

The longitudinal ultrasonic attenuation and velocity were measured in trigl- cyine sulfate (TGS) single crystal over the temperature range of 30--l00deg.C. It was found that the peak of the relative ultrasonic attenuation near the second- order phase transition is lower in the heating process than that in the cooling process, and its height decreases with the increasing frequency. Hence, the peak should be associated with the process of changing temperature and the measuring frequency. Another ultrasonic attenuation peak, which corresponds to the PD_2 peak discovered by other scientists, was also found in the experi- ment at 5.56 MHz. However, in experiments at l3.3 MHz and 30.8 MHz, such a peak was not observed. Considering these phenomena, it is suggested that this peak does not occur above the Curie point and is closely related to the interaction between domains.