X-RAY-DIFFRACTION AND HIGH-RESOLUTION TRANSMISSION ELECTRON-MICROSCOPY STUDY ON A-SITE ORDERING OF LANTHANUM-MODIFIED LEAD-ZIRCONATE-TITANATE RELAXOR

The ordering behavior of La-modified lead zirconate titanate relaxer (PLZT 9/65/35) was investigated by use of an x-ray diffractometer (XRD) and high-resolution transmission electron microscopy (HRTEM). It was shown that a {h + 1/2, k + 1/2, 0}-type superlattice exists both in the x-ray diffraction pattern and selected area electron diffraction (SAED) image. High-resolution electron micrographs further demonstrated the existence of the superlattice and exposed the ordered and disordered regions in the lattice level. A model referring to an A-site body-centered pseudo-cubic superstructure was proposed.