Crystal Orientation Dependence of Piezoelectric Properties in Lead Zirconate Titanate: Theoretical Expectation for Thin Films

Abstract

Crystal orientation dependence of piezoelectric properties has been calculated phenomenologically for lead zirconate titanate (PZT) in the three-dimensional space. The calculation has been made for tetragonal PZT 40/60 (40% PZ and 60% PT) and rhombohedral PZT 60/40 compositions. The maximum longitudinal piezoelectric constant d 33 and electromechanical coupling factor k 33 in the rhombohedral composition were found to be at 57° and 51° angles, respectively, canted from the spontaneous polarization direction. This suggests that thin film piezoelectric actuators or sensors should employ a rhombohedral composition with the perovskite [100] epitaxially-oriented configuration.