Hard and soft composition lead zirconate titanate thin films deposited by pulsed laser deposition

Lead zirconate titanate thin films offer considerably larger piezoelectric coefficients than do ZnO, and so are attractive for microelectromechanical sensors and actuators. To date, much of the research in this field has concentrated on undoped PZT. In this work, PZT films grown from both hard and soft PZT targets have been deposited on platinum coated silicon wafers by pulsed laser deposition so that the effect of doping on the properties can be determined. Dielectric constants of 1000-1500 are regularly achieved in both types of films, with loss values varying from 0.01 for soft films to 0.03 for hard films. Remanent polarizations are typically 30 μC/cm² for both types of films with no observable difference in coercive fields. When subjected to approximately 140 MPa of biaxial tension and compression, only small (approximately 5%) reversible changes were observed, indicating a lack of substantial domain reorientation in the films.