POLAR AND CHEMICAL DOMAIN STRUCTURES OF LEAD SCANDIUM TANTALATE (PST)

Abstract

The local structure of chemical and polar domains and domain walls is determined directly by atomic resolution high-resolution electron microscopy (HRTEM). Thus the Pb, Ta, and Sc atomic positions may be located in the images of very thin crystals. Furthermore, the Pb cation displacements away from the ideal perovskite A-site have been measured directly for the first time. Local variations in polarization direction may be mapped directly off the images, provided certain electron optical conditions are met. The results are relevant to recent theories of polar-glass behaviour in relaxor-type complex oxide functional ceramics.