Correlation between electric-field-induced phase transition and piezoelectricity in lead zirconate titanate films

We observed that electric field induces phase transition from tetragonal to rhombohedral in polycrystalline morphotropic lead zirconate titanate (PZT) films, as reported in 2011 for bulk PZT. Moreover, we evidenced that this field-induced phase transition is strongly correlated with PZT film piezoelectric properties, that is to say the larger the phase transition, the larger the longitudinal piezoelectric coefficient d33,eff. Although d33,eff already reaches 130-1500.16em0expm/V, our observation suggests that one could obtain larger d33,eff values, namely 2500.16em0expm/V, by optimizing the field-induced phase transition thanks to composition fine tuning as close as possible to the morphotropic phase boundary.