Тип публикации: доклад, тезисы доклада, статья из сборника материалов конференций
Конференция: Electron Microscopy and Analysis Group Conference (EMAG); Manchester, ENGLAND; Manchester, ENGLAND
Год издания: 2015
Идентификатор DOI: 10.1088/1742-6596/644/1/012004
Ключевые слова: Crystal structure, Dyes, Electron microscopy, High resolution transmission electron microscopy, Lithium, Neutron diffraction, Perovskite, Positive ions, Scanning electron microscopy, Transmission electron microscopy, Hexagonal perovskite, Hexagonal unit cells, Microwave assisted, Quasi-one dimensional, Scanning transmission electron microscopy, Solid-state synthesis, Structural solutions, X-Ray and neutron diffraction, Manganese
Аннотация: A new hexagonal perovskite, Ba7Li1.75Mn3.5O15.75, has been synthesised using microwave-assisted solid-state synthesis. Its crystal structure has elements typical for the layered hexagonal perovskites and quasi-one-dimensional oxides, hence representing a new polytype. Structural solution based on simultaneous refinement of X-ray anПоказать полностьюd neutron diffraction data shows that Ba7Li1.75Mn3.5O15.75 crystallizes in a hexagonal unit cell with parameters a = 5.66274(2) A and = 16.7467(1) A (V = 465.063(4) a(3)). Columns of faceshared octahedra occupied by Mn4+, Li+ cations and vacancies along the. axis are separated in the ab plane by barium atoms, so that every sixth layer, the coordination of Mn5+ and Li+ changes to tetrahedral. Separation of Mn4+ and Mn5+ cations in two distinct structural positions makes the structure unique. A scanning transmission electron microscopy study revealed the formation of a rhombohedrally centered supercell, which might be attributed to the ordering of manganese and lithium atoms among cationic sites.
Журнал: ELECTRON MICROSCOPY AND ANALYSIS GROUP CONFERENCE (EMAG2015)
Выпуск журнала: Vol. 644
ISSN журнала: 17426588
Место издания: BRISTOL
Издатель: IOP PUBLISHING LTD