Piezoelectric temperature coefficient of transverse resonance mode and thermal depoling investigations on (Pb,Ca)TiO₃ solid solutions

ABSTRACT

This work uses the electromechanical resonance technique to investigate the piezoelectric properties of Pb_0.55Ca_0.45TiO₃ ceramics as a function of temperature. The elastic compliance coefficient, s₁₁^E, and the transverse electromechanical coupling factor, k₃₁, were calculated based on the harmonic oscillator model of piezoelectric vibrating sample. In addition to the analysis of the temperature dependence of the piezoelectric response, the thermal depoling current and the real and imaginary parts of the dielectric permittivity as a function of the temperature were investigated. The thermal stability of the piezoelectric response was determined and the non-accordance of the temperature anomalies of k₃₁, s₁₁^E, dielectric and pyroelectric coefficients were discussed.

KEYWORDS:

• Calcium lead titanates
• temperature coefficient
• electromechanical coupling
• pyroelectric current
• elastic compliance

Acknowledgments

This work was supported by the Brazilian foundation CAPES and CNPq (Proc. n. 462149/2014-5) and by São Paulo state foundation FAPESP (Proc. n. 2008/04025-0). The authors are grateful to Mr. Francisco J. Picon (DF-UFSCar), Mrs. Natalia A. Zanardi (DF-UFSCar) and Mr. José A. L. da Rocha (IFSC-USP) for the technical assistance and Mr. Lauro F. Rodrigues for the protocol of the sample processing.