Reversible and irreversible piezoelectric and ferroelectric response in ferroelectric ceramics and thin films

In this article, a novel characterization method, the separation between reversible and irreversible contributions, is applied to the piezoelectric and ferroelectric response of ferroelectric ceramics and thin films. The reversible contributions are determined by the measurement of appropriate small-signal properties, e.g. the piezoelectric coefficient for the piezoelectric response and the small-signal capacitance for the polarization response of the material, and compared to the corresponding large signal properties (i.e. the strain–field dependence and polarization–field dependence, respectively). The comparison between thin films and bulk ceramics indicates that the non-180° domain wall motion in ferroelectric thin films is reduced compared to bulk ceramics.