Modeling of piezoelectric ceramic vibrators including thermal effects. Part I. Thermodynamic property considerations

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 the piezoelectric constants obtained by static and dynamic measurements cannot be explained by the difference between isothermal and isentropic processes.