Optical Activity and Phase Transition of Pb1-xLax(ZryTiz)1-x/4O3

Abstract
Electric field dependences of optical activity and birefringence of Pb0.92La0.08(Zr0.7Ti0.3)0.98O3(PLZT(8/70/30)) were studied using the high-accuracy universal polarimeter (HAUP) method in a temperature region between 0° C and 90° C. PLZT(8/70/30) was optically active in the low-temperature and inactive in the high-temperature phases. Furthermore it was revealed that gyration and birefringence in the low-temperature phase manifested typical butterfly hysteresis loops with respect to electric fields. From analysis of Weissenberg photographs, the ceramics of both high- and low-temperature phases were found to consist of crystallites which were distributed in equal weight along the total solid angles. Using the combined evidence from HAUP and X-ray methods, it was clarified that the classes of the high- and low-temperature phases are T h and C3, respectively.