The Tetragonal-Cubic Phase Transition and Coalescence of Double Topographs in Top-Seeded (001) BaTiO3 Single Crystals Using White Synchrotron X-Radiation Topography (WSRT)

Back reflection double (402), (402)′ WSR topographs of (tetragonal) top-seeded BaTiO3 single crystals are recorded as the temperature increased to the Curie point (Tc). In addition to the usual (complementary) a'- and c-domain topographs, small “secondary domains” are observed within the c-domains. Their misorientation is in the same sense but much smaller than that of the a'-domains and is similarly temperature dependent. Beyond Tc the (cubic state) topographs are free of domains and clearly show the presence of relatively broad line dislocations directed along [100] and [010]. Alternative quasi lifetime transmission topographs successively show crack formation caused by strong reverse [001] dc poling