Dielectric properties of (Sr_0.7Pb_0.3)TiO₃ ceramics with relaxor-like character

ABSTRACT

Dielectric properties of (Sr_0.7Pb_0.3)TiO₃ ceramics were investigated up to 100 kHz down to −260 °C along with temperature dependent thermal strain, X-ray diffraction peaks, and hysteresis loops. The (Sr_0.7Pb_0.3)TiO₃ ceramic showed almost frequency independent relative dielectric permittivity, the Curie point at 10 °C from the cubic to the tetragonal, and dielectric maxima with the second-order phase transition, more than 30000. The Curie-Weiss behavior showed deviation near the Curie point owing to microscopic polarization similarly observed in relaxor ferroelectrics. Loss tangent measurements showed low values in the paraelectric phase, less than 0.0005, and three anomalies in the ferroelectric phase.

KEYWORDS:

• Strontium lead titanate
• Curie-Weiss
• dielectric
• phase transition
• relaxor

Acknowledgments

Partial financial support was provided by the DARPA under contract No. DABT 63-98-1-002. One of the authors (Y. S.) expressed acknowledgment to Dr. G. G. Johnson, Jr. and Mrs. Nichole M. Wonderling for the help in XRD measurements, and Dr. Arsen Soukiassian for the help in translating papers in Russian into English.