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Ordering of calcium and vacancies in calcium catapleiite CaZr[Si3O9] aEuro cent 2H(2)Oстатья
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: 24 октября 2016 г.
- Авторы: Aksenov S.M., Portnov A.M., Chukanov N.V., Rastsvetaeva R.K., Nelyubina Yu V., Kononkova N.N., Akimenko M.I.
- Журнал: Crystallography Reports
- Том: 61
- Номер: 3
- Год издания: 2016
- Издательство: Maik Nauka/Interperiodica Publishing
- Местоположение издательства: Russian Federation
- Первая страница: 376
- Последняя страница: 382
- DOI: 10.1134/S1063774516030020
- Аннотация: A sample of holotypic calcium catapleiite from the Burpala alkaline massif (Northern Baikal, Russia) is studied by single crystal X-ray analysis at 120 K and IR spectroscopy. The empirical formula of calcium catapleiite is Ca0.97Na0.02Zr1.01Si3O9 aEuro cent 2H(2)O (Z = 4). The X-ray diffraction study confirms the orthorhombic unit cell with the following parameters: a = 7.406(1), b = 12.687(1), and c = 10.112(1) ; V = 950.1(2) (3); space group Pbnn. The crystal structure is refined in the anisotropic approximation of atomic displacement parameters using 1177 reflections with I > 2 sigma(I) to the final R = 2.91%. The structure of calcium catapleiite under study is based on the microporous heteropolyhedral framework formed by ZrO6 octahedra and threemembered silicon-oxygen rings [Si3O9]. It is on the whole analogous to the structures of the samples studied earlier, but differs from them by a high degree of ordering of calcium and vacancies at extraframework positions. The distribution of calcium over Ca1 and Ca2 positions in the calcium catapleiite structure leads to the formation of zigzag chains of the aEuro broken vertical bar Da1-Zr-Ca1-ZraEuro broken vertical bar and aEuro broken vertical bar Da2-h-Ca2-a-aEuro broken vertical bar types. Low occupancy of the Ca2 position and its alternation with the vacancy are prerequisites for potential Ca2+ cationic conduction.
- Добавил в систему: Аксенов Сергей Михайлович