Piezoelectric properties of rhombohedral Pb(Zr, Ti)O3 thin films with (100), (111), and “random” crystallographic orientation

The longitudinal d33 piezoelectric coefficient was studied in rhombohedral Pb(Zr0.6Ti0.4)O3 thin films with (111), (100), and “random” orientation. The largest d33 was found in (100)-oriented films and the smallest along the polarization direction in (111)-oriented films. These results are in a good qualitative agreement with recent theoretical predictions [Du, Zheng, Belegundu, and Uchino, Appl. Phys. Lett. 72, 2421 (1998)]. The field dependence of d33 was also investigated as a function of crystallographic orientation of the films. It was found that (100)-oriented films with the highest piezoelectric coefficient exhibit the weakest nonlinearity. Observed variation in the piezoelectric nonlinearity with film orientation can be fully explained by taking into account domain-wall contributions, which are dependent on film orientation.