Toward a unified description of nonlinearity and frequency dispersion of piezoelectric and dielectric responses in Pb(Zr,Ti)O3

A phenomenological approach is proposed describing both nonlinearity and frequency dispersion in dielectric and piezoelectric properties of lead zirconate titanate, Pb(Zr,Ti)O3 (PZT), thin films and ceramics. The approach couples the frequency dependent response in form of the power law, 1/ωβ, with the rate-independent nonlinear response described by the Rayleigh law. The main experimental trends are well described by the model.