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New isoformula borates with similar structures and different properties - acentric nonlinear optical KGd[B6O10(OH)2] and centrosymmetric KHo[B6O10(OH)2статья
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: 19 сентября 2015 г.
- Авторы: Belokoneva E.L., Topnikova A.P., Stefanovich S.Yu, Dobretsova E.A., Volkov A.S., Dimitrova O.V.
- Журнал: Solid State Sciences
- Том: 46
- Год издания: 2015
- Издательство: Elsevier BV
- Местоположение издательства: Netherlands
- Первая страница: 43
- Последняя страница: 48
- DOI: 10.1016/j.solidstatesciences.2015.05.012
- Аннотация: Single crystals of two new borates, KGd[B6O10(OH)2] and KHo[B6O10(OH)2], have been synthesized in multi-components hydrothermal solutions at controlled pH. Similar in unit cell, the structures differ in relation to the symmetry: K,Gd-structure is solved in acentric space group P-62m, while K,Ho-structure is centrosymmetric, P-31m. Polyborate anionic layers of new type from tetrahedra and triangles are identical; however multiplication of the layers by symmetry is differently produced either by mirror plane or the inversion center. The layers of oxygen-boron tetrahedra and triangles in K,Gd- and K,Ho-borates are connected by GdO6 prisms and HoO6 octahedra, correspondingly. Second-order nonlinearity is clearly manifested by intensive SHG effect in K,Gd-borate, and absent in K,Ho-borate. K- and B-triangles positions are statistically occupied in both structures. It is noticed that an ordered model of K,Gd-structure is possible with the unit cell tripled along c-axis, symmetry P31 and polar orientation of the B-triangles. In any model, absence of center of symmetry and following different symmetrical ordering in crystal structure both distinguish K,Gd-borate from its similar Ho-counterpart, and also explain their different properties.
- Добавил в систему: Стефанович Сергей Юрьевич