New borates with similar structures and different properties – acentric nonlinear optical KGd[B6O10(OH)2] and centrosymmetric KHo[B6O10(OH)2]тезисы доклада

Дата последнего поиска статьи во внешних источниках: 22 февраля 2019 г.

Работа с тезисами доклада


[1] New borates with similar structures and different properties – acentric nonlinear optical kgd[b6o10(oh)2] and centrosymmetric kho[b6o10(oh)2] / T. Anastasiia, B. Elena, D. Olga et al. // Acta Crystallographica (31th European Crystallographic Meeting, Book of abstracts). — Vol. 74 of A. — Blackwell Publishing Inc UK, 2018. — P. e234. 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.

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