Correlation between domain evolution and asymmetric switching in epitaxial Pb(Zr₀.₅₂Ti₀.₄₈)O₃ thin films

Abstract

The process-induced domain evolution and asymmetric switching in epitaxial Pb(Zr₀.₅₂Ti₀.₄₈)O₃(PZT) thin films have been studied by reciprocal space mapping, transmission electron microscopy, high-temperature x-ray diffraction, and the polarization-electric field hysteresis loop measurements. After annealing at reduced oxygen pressures, it was evidenced that an oxygen loss at the PZT bottom interface can occur at temperatures well below the Curie temperature T[sub C], and more importantly, the oxygen loss can induce a large positive voltage offset and drive simultaneously the polydomain formation in the PZT films. Our results indicate that the structure evolution is correlated with the coercive voltage shift, and an oxygen-loss-related internal stress at the interface would be responsible for the large internal electric field in epitaxial PZT films.