Observation of Piezoelectric Relaxation in Ferroelectric Thin Films by Continuous Charge Integration

A continuous charge integration technique is used to measure the effective longitudinal piezoelectric coefficient (d 33) of thin films. Measurements are performed by applying a static force normal to the films and recording the stress-induced polarization with a charge integrator. Measurements for the as-deposited PbZr0.53Ti0.47O3 (PZT) thin films show that the piezoelectric effect is strongly time-dependent and the relaxation is well described by the stretched exponential law. It was demonstrated that the continuous charge integration technique is highly useful for the characterization of the piezoelectric properties of thin films.