E. Belokoneva, S. Stefanovich, O. Dimitrova
Nov 1, 2012
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0
Influential Citations
31
Citations
Journal
Journal of Solid State Chemistry
Abstract
Abstract Three optically uniaxial non-centrosymmetric potassium compounds, iodate K[IO 3 ] and two borates K 3 [B 6 O 10 ]Br, KTa[B 4 O 6 (OH) 4 ](OH) 2 ·1.33H 2 O have been synthesized and characterized by single-crystal X-ray diffraction. The materials were synthesized through hydrothermal techniques using initial reagents and mineralizers. All the compounds are trigonal-hexagonal: the space groups are R3 (K[IO 3 ]), R3m (K[B 6 O 10 ]Br) and P-62m (KTa[B 4 O 6 (OH) 4 ](OH) 2 ·1.33H 2 O). Powder second-harmonic generation (SHG) measurements on crystals, using 1064 nm Nd:YAG laser radiation, indicate the materials are all phase-matchable and have strong second-order nonlinearities. The correlation with the perovskite structure has been found and described for K,Br-borate and K-iodate. Structure-properties relation is discussed and attributed to stereo-active lone-pair on I 5+ and asymmetrical bonds in the compounds. The role of K atoms is pronounced from crystal chemistry point of view, contributing optical nonlinearities.