Phase–field modelling of 180° “Bloch walls” in rhombohedral BaTiO₃

This article describes investigations of 180° walls in rhombohedral BaTiO3 in the framework of generalized Ginzburg–Landau–Devonshire model, using phase-field simulation approach. It is demonstrated that the 180° wall with the normal parallel to [1−10] direction has a Bloch-like character. Its domain profile can be understood as a pair of very close 71° and 109° walls, which can be continuously separated by a strong transverse electric field. The intermediate region can be considered as a few nanometers thick monoclinic domain.