Effect of lattice-misfit strain on the process-induced imprint behavior in epitaxial Pb(Zr₀.₅₂Ti₀.₄₈)O₃thin films

Abstract

The effect of lattice-misfit strain on the process-induced imprint behavior in Pb(Zr₀.₅₂Ti₀.₄₈)O₃ (PZT) capacitors with Pt (top), and SrRuO₃, La₀.₇Sr₀.₃MnO₃or LaNiO₃ (bottom) electrodes has been studied. With the different oxide electrodes and by changing the deposition oxygen pressure, various lattice-misfit strains in the epitaxial PZT films have been produced. It was found that after in situ annealing at reduced oxygen pressures, the capacitors showed an increased voltage offset in the polarization-electric field hysteresis loops with increasing the misfit strain, irrelevant to the oxide electrodes employed, while lattice disorder at the bottom interface can effectively eliminate the voltage shift. Our results suggest that the imprint behavior is caused by oxygen loss via dislocations generated by the misfit strain relaxation at the growth temperature.