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Characteristic features of polytypism in compounds with the La18W10O57-type structureстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 3 июля 2019 г.
- Авторы: Novikova Nataliya E., Sorokin Timofei A., Antipin Alexander M., Bolotina Nadezhda B., Alekseeva Olga A., Sorokina Nataliya I., Voronkova Valentina I.
- Журнал: ACTA CRYSTALLOGRAPHICA SECTION C-STRUCTURAL CHEMISTRY
- Том: 75
- Год издания: 2019
- Издательство: John Wiley & Sons Inc.
- Местоположение издательства: United States
- Первая страница: 740
- Последняя страница: 749
- DOI: 10.1107/S2053229619006107
- Аннотация: Crystals with the La(18)W(10)O(57-)type structure (6H and 5H polytypes) were obtained by a self-flux method from high-temperature solutions. Some of the crystal samples were studied by single-crystal X-ray structure analysis. The diffraction patterns indicated that two phases co-exist in each sample. The hexagonal lattices have a common period of a approximate to 9.0 angstrom and are non-equal in length but have equally oriented superstructure periods 6c (phase I) and 5c (phase II), c approximate to 5.4 angstrom. The structures of phases I and II were solved in the symmetry groups P (6) over bar 2c and P321, respectively, based on the X-ray data for crystals I and II, with predominant content of the first and second phase. The motif of isolated WO6 prisms with Watoms on the cell edges is common to both phases. WO6 octahedra, both isolated and joined by faces, are distributed along the c axis within the unit cells. Phase I contains extra layers of isolated WO6 octahedra compared to phase II. Tungsten sites in joined octahedra are disordered and partially occupied. Disordering is more expressed in phase II, which in return contains rather more W and O per atom of La. The refined chemical compositions are La18W10O57 for I and La15W8.5O48 for II.
- Добавил в систему: Воронкова Валентина Ивановна