Ilene J. Busch-Vishniac
Mech. Eng. Dept., Univ. of Texas at Austin, Austin, TX 78712
The thermodynamic characteristics of piezoelectric ceramics are investigated by considering two thermodynamic material property models: isentropically linear and isothermally linear models. Those two models are two possible interpretations of the data on temperature-dependent linear coefficients of piezoelectric ceramics. Thermodynamic differences of the two models are examined and effects of the thermo-electro-mechanical couplings are evaluated in examples. Application of the thermo-electro-mechanical model to PZT4 shows that the difference observed in piezoelectric constants obtained by static and dynamic measurements cannot be explained by the difference between isothermal and isentropic processes.