According to the crystal structure, 3 types of translation and 2 types of orientation domain boundaries were to be expected in La2/3Ca1/3MnO3 as a result of phase transitions. However, the most easily observed domain boundaries in bulk samples were [½½½] translation boundaries (or antiphase boundaries) and 90° domain boundaries, while [½0½] and [0½0] translation boundaries were rarely observed. This was explained here by considering the tilting modes of the O octahedra in the structure. It was found that there was no distortion of the nearby O octahedra if the [½½½] translation boundaries occupied (010) boundary planes and the 90° domain boundaries were on {101} planes; making them low-energy boundary planes and therefore easy to form. On the other hand, [½0½] and [0½0] translation boundaries introduced distortion into the O octahedra, which required breaking the tilting modes in the boundary areas. They were therefore high-energy boundary planes, which were rarely observed. These conclusions were supported by transmission electron microscopy data.

Translation and Orientation Domain Boundaries in La2/3Ca1/3MnO3. Y.Ding, Z.L.Wang: Philosophical Magazine, 2006, 86[16], 2329-42