Nonlinearity of soft PZT piezoceramic for shear and torsional actuator applications

The temperature dependence of piezoelectric and dielectric properties of a soft PZT piezoceramic is analyzed in view of the ac-field dependence of the effective coefficients d₁₅ and ε₁₁ respectively. The ac-field dependence of both coefficients obeys power laws in the whole temperature range 77K<T<303 K examined. The obtained exponents indicate a violation from the classical Rayleigh law. The result is discussed in terms of the dynamics of domain walls interacting with the defect structure of the piezoceramic