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IR spectroscopy of rare-earth aluminum borates RAl3(BO 3)4 (R = Y, Pr-Yb)статья
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: 31 октября 2014 г.
- Авторы: Dobretsova E.A., Borovikova E.Yu, Boldyrev K.N., Kurazhkovskaya V.S., Leonyuk N.I.
- Журнал: Optics and Spectroscopy (English translation of Optika i Spektroskopiya)
- Том: 116
- Номер: 1
- Год издания: 2014
- Издательство: Optical Society of America
- Местоположение издательства: United States
- Первая страница: 77
- Последняя страница: 83
- DOI: 10.1134/S0030400X14010068
- Аннотация: Abstract—Rare-earth aluminum borates RAl3(BO3)4 (R = Y, Nd–Yb) obtained by spontaneous high-temperature flux crystallization form two polytype modifications described by the space groups R32 and C2/c. They differ in the symmetry versions in mutual arrangement of layers. These borates have been investigated by mid- and far-IR spectroscopy in combination with factor-group analysis of the vibrations of BO3 triangles; translational motions of Al3+, R3+ (Y, Nd–Yb), and BO3 groups; and BO3 rotations. Rare-earth aluminum borates are assigned to different space groups according to their IR spectra. Borates with large rare-earth Nd and Pr cations are crystallized into the space group C2/c, while borates with smaller (Y, Sm–Yb) ions are crystallized into the space group R32. The rombohedral structure of the latter compounds includes monoclinically ordered domains, as is evidenced by the presence of monoclinic-phase bands in the IR spectrum. NdAl3(BO3)4 and SmAl3(BO3)4 can form both monoclinic and rhombohedral polytypes. The IR spectrum of the monoclinic SmAl3(BO3)4 phase contains bands due to the rhombohedral phase, while the IR spectrum of NdAl3(BO3)4 (which is described by the space group R32) contains bands due to the monoclinic polytype. The presence of domains with another arrangement of layers in the polytype structure is a characteristic sign that corresponds to the order–disorder theory.
- Добавил в систему: Леонюк Николай Иванович