In-situ study on piezoelectric responses of sol-gel derived epitaxial Pb[Zr, Ti]O3 thin films on Si substrate

Pb[Zr,Ti]O3 (PZT) thin films with the Zr/Ti ratio of 45/55, 52/48, and 60/40 (PZT(45/55), PZT(52/48), and PZT (60/40), respectively) are deposited on (001)SrRuO3/(001)Pt/ZrO2/Si by sol-gel method. We confirm that the epitaxial (001)Pt electrode facilitate the epitaxial growth of the PZT thin films along the c-axis direction. Basic characteristics such as structural, dielectric, and ferroelectric properties are examined. Furthermore, direct and converse piezoelectric properties are evaluated using effective transverse piezoelectric coefficients, |e31,f|. In particular, the epitaxial PZT thin films manifest a dependence of the converse |e31,f| on applied voltages with the values as follows; 9.7-11.5 C/m2, 11.2-12.5 C/m2, and 11.7-12.3 C/m2 for the epitaxial PZT(45/55), PZT(52/ 48), and PZT(60/40), respectively. Moreover, by analyzing bias-resolved in-situ reciprocal space map (RSM) obtained from synchrotron radiation X-ray diffraction (SR-XRD) which allows for the understanding on the transition of crystal structures, we explore the voltage-induced contributions for the converse |e31,f|.