Transmission electron microscopy study of the domain structures of the relaxor ferroelectric PMN-PT 67/33 single crystals

Abstract The domain configurations of two different relaxor ferroelectric single crystals with the nominal composition (0.67)Pb(Mg⅓, Nb⅔)O3-(0.33)PbTiO3 (PMN-PT 67/33) grown by a modified-Bridgeman method were studied by transmission electron microscopy (TEM). The crystal structures of the samples were also investigated by X-ray diffraction (XRD). A TEM image recorded from one of the specimens along the [001] direction showed lamella-shaped 90° domains, indicating the presence of a tetragonal phase in PMN-PT 67/33. TEM images recorded from the second single crystal of PMN-PT 67/33 showed domains of irregular configurations and morphologies with orientations close to the <001> directions. Analysis indicates that the crystal with irregular domain configurations is rhombohedral. The thickness of the domains in the rhombohedral phase varies from one hundred to a few hundred nanometers. The domain patterns from this crystal indicate complicated angular relationships of 70.5°, 109.5° and 180° between the dipoles, which have possible orientations along the <111> directions.