Twinning domain in 67Pb(Mg_1/3Nb_2/3)O₃–33PbTiO₃ ferroelectric complex perovskite crystal grown by the Bridgman method

Single crystals of 67Pb(Mg_1/3Nb_2/3)O₃–33PbTiO₃ (PMN-PT, PMNT) relaxor-based complex perovskite solid solution grown by Bridgman method have pseudo-cubic symmetry under ambient conditions. Examination by means of polarized light microscopy showed that the microstructure of the crystals was dominated by a large number of coarse twin domains. It was confirmed that the most common composition planes were {110} in addition, {112} planes were also observed. These twins may be associated with the transformation of PMNT complex perovskite from the cubic to tetragonal upon a decrease in temperatures. The morphology of the domain structure may be explained from the theory of martensitic transformation.