Investigation of domain structure of SrBi₂Ta₂O ₉ single crystals via polarized optical and piezoelectric force microscopy

High-quality SrBi₂Ta₂O₉ (SBT) single crystals were grown via high-temperature self-flux solution method. The crystals had a shape of platelets with c-axis normal to the major face according to x-ray diffraction. The optical observations with polarized light revealed complex domain patterns with mutually orthogonal domains in (a, b)plane. The twin boundaries with rounded borders may correspond to microtwinning at the scale of the size of the elementary cell. Piezoelectric force microscopy revealed an irregular domain configuration consisting of fine antiparallel domains oriented along [100] direction.