K2(NbO)2Si4O12: A new material for non-linear optics
K2(NbO)2Si4O12: A new material for non-linear optics
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DOI：
10.1080/00150199108209415
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发表时间：
1991-12
期刊：
影响因子：
0.8
通讯作者：
M. Crosnier;D. Guyomard;A. Verbaere;Y. Piffard;M. Tournoux
中科院分区：
文献类型：
--
作者：
M. Crosnier;D. Guyomard;A. Verbaere;Y. Piffard;M. Tournoux
环四硅酸钾晶体K2（NbO）2Si4O12，非中心对称极性空间群P4bm，a = 8.7404（8）A，c = 8.136（1）A，Z = 2。该结构的偏心特征主要是由于沿四重轴沿着的一系列短（正丙基）和长Nb-O键。对小晶体的光学研究表明，透明度范围从0.3 μ m延伸到4.5 μ m，并且它们是正单轴的。利用YAG Nd激光器的1.06 μ m谱线对多晶样品进行了二次谐波产生随温度变化的实验。它们表明在1080 [ddot] C（设备的极限）下仍然获得相位匹配条件。K2（NbO）2Si4O12在1180 [ddot] C下全等熔化，表现为相当惰性和化学稳定。
Abstract The potassium niobyl cyclotetrasilicate K2(NbO)2Si4O12 crystallizes in the non-centrosymmetrical polar space group P4bm with a = 8.7404(8) A, c = 8.136(1) A, Z = 2. The acentric character of the structure is mainly due to a sequence of short (niobyl) and long Nb-O bonds along the 4-fold axes. Optical studies on small crystals have shown that the transparency range extends from 0.3 to 4.5 μm and that they are positively uniaxial. Second harmonic generation tests, as a function of temperature, have been performed on a polycrystalline sample with use of the 1.06 μm line of a YAG-Nd laser. They show that phase matching conditions are still obtained at 1080[ddot]C (limit of the equipment). K2(NbO)2Si4O12 melts congruently at 1180[ddot]C and appears as rather inert and chemically stable.