Crystallographic domain structures associated with charge ordering transition in Pr0.55Ca0.45MnO3 and Nd0.5Sr0.5MnO3

We have made crystallographic analysis for microstructures formed by charge ordering transition in Pr0.55Ca0.45MnO3 and Nd0.5Sr0.5MnO3 whose changes of crystal structure associated with a charge ordering transition are quite different from each other. It was found that charge-ordered phases in Pr0.55Ca0.45MnO3 and Nd0.5Sr0.5MnO3 are composed of crystallographic domains with {1 0 1}CO (CO represents a charge-ordered phase) twinning planes and {1 1 2}CO twinning planes. The twinning planes of Pr0.55Ca0.45MnO3 and Nd0.5Sr0.5MnO3 correspond to {1 1 0} planes of cubic perovskite structure such as BaTiO3, if the crystal structures in the charge-ordered phases are applied to the unit cell of cubic perovskite structure.