In this paper we report coincident anomalies in both dielectric response and sound velocities in strontium titanate around three temperatures 16, 37, and 65 K. The anomalies occur in both single-crystal specimens and ceramics, so they cannot be related to grain boundary mechanisms, but they are enhanced by bismuth doping. The results indicate that the dielectric and ultrasonic anomalies are dynamic and not static. The physical nature of the anomalies was briefly discussed.

• Received 4 June 1998

DOI:https://doi.org/10.1103/PhysRevB.59.6661