Orientation dependence of ferroelectricity of epitaxially grown Pb(ZrxTi1-x)O3 thin films prepared by metalorganic chemical vapor deposition

Epitaxial PZT films with (001)- and (100)-, (101)-,(110)- and (111)-orientations were grown on (100)SrRuO₃//(100)SrTiO₃, (110)SrRuO₃//(110)SrTiO₃ and (111)SrRuO₃//(111)SrTiO₃ substrates, respectively. The two composition films with Zr/(Zr+Ti) ratios of 0.42 and 0.68 were prepared with the Pb/(Pb+Zr+Ti) ratio of 0.5. Well-saturated and good square shape hysteresis loops with a large ferroelectricity of the remanent polarization (Pr) above 40 μC/cm² were observed for all films. The Pr increased in the following order: (101)-, (111)- and (001)-orientations for the film with the Zr/(Zr+Ti) ratio of 0.42 and (100)-, (110)- and (111)-orientations for the Zr/(Zr+Ti) ratio of 0.68. On the other hand, the Ec value mainly depended on the Zr/(Zr+Ti) ratio and not on the orientation of the film, the Ec value of the film with a Zr/(Zr+Ti) ratio of 0.42 was larger than that of 0.68. The saturation behavior did not strongly depend on the orientation, especially for the films with the Zr/(Zr+Ti) ratio of 0.42. The (101)-oriented film with the Zr/(Zr+Ti) ratio of 0.42 and (100)- and (111)-oriented films with 0.68 did not show deterioration up to 10¹⁰ switching cycles