Transmission electron microscopy and structural phase transitions in anion-deficient perovskite-based oxides.

摘要: This review deals with the structural transitions arising in anion-deficient Mn- and Cu-based perovskites when changing anion content. Special attention is devoted to local structure of such materials, studied electron diffraction high-resolution microscopy. Using examples three-dimensional or layered manganites cuprates, it shown that oxidation/reduction reactions compounds are accompanied by formation domain structures. Fragmentation into domains can have intrinsic reasons, related loss symmetry elements due ordering vacancies, because simultaneous realization several different patterns close energies. When extra anions inserted at low temperatures, limited diffusion ability also results appearance structures from a inhomogeneity distribution. The relevance investigation for correct interpretation discussed.