Preparation and properties of thin ferroelectric films of PLZT

Abstract

PLZT films are prepared by r f diode sputtering from a target, eight inches in diameter, manufactured by hot pressing of ceramic powder. The parameters of this process, e.g. gas pressure, substrate bias, power and excess PbO built into the target, have a great influence on the stoichiometry of the films. Substrate temperatures above 500°C during the process are necessary to obtain perovskite ferroelectric films in situ. A thermal annealing destroys the surface of the films and they can no longer be used for optical application. The ferroelectric behaviour is examined by dielectric measurements versus temperature and frequency and by studies of hysteresis loops respectively. The results are compared with the values of ceramics. The longitudinal electro-optic effect of the films is measured in transmission.