Wang Qian, Yang Fei, Wang Xing, Zhou Jing, Ju Jia, Huang Ling, Gao Daojiang, Bi Jian, Zou Guohong
College of Chemistry and Materials Science , Sichuan Normal University , Chengdu 610068 , People's Republic of China.
Institute of Chemical Materials , China Academy of Engineering Physics , Mianyang 621900 , People's Republic of China.
Inorg Chem. 2019 May 6;58(9):5949-5955. doi: 10.1021/acs.inorgchem.9b00271. Epub 2019 Apr 9.
By introduction of K, Rb, and Cs cations into the classical commercial nonlinear optical crystal LiBO (LBO), the series of novel mixed-alkali-metal borates LiK[BO(OH)] (K-LBO), LiRb[BO(OH)] (Rb-LBO), and LiCs[BO(OH)] (Cs-LBO) have been obtained under hydrothermal conditions. The steric hindrance effect generated by the introduction of large alkali-metal cations and partial substitution of small Li cations broke the three-dimensional (3-D) framework of [BO] borate-oxygen clusters in LBO and resulted in a structure rearrangement to produce infrequent [BO] 2-D layers. The unique layered structure induced an increase in birefringence in A-LBOs (A = K, Rb, Cs), which is favorable for phase matching during second-harmonic generation. All three compounds are potential deep-ultraviolet nonlinear optical materials, which was proved by UV-vis-NIR diffuse reflectance spectroscopy and second-harmonic-generation measurements.
通过将钾、铷和铯阳离子引入经典的商用非线性光学晶体LiBO（LBO）中，在水热条件下获得了一系列新型混合碱金属硼酸盐LiK[BO(OH)]（K-LBO）、LiRb[BO(OH)]（Rb-LBO）和LiCs[BO(OH)]（Cs-LBO）。引入大的碱金属阳离子所产生的空间位阻效应以及小的锂阳离子的部分取代，打破了LBO中[BO]硼酸盐-氧簇的三维（3-D）框架，并导致结构重排，从而产生了罕见的[BO]二维层。独特的层状结构导致A-LBOs（A = K、Rb、Cs）的双折射增加，这有利于二次谐波产生过程中的相位匹配。通过紫外-可见-近红外漫反射光谱和二次谐波产生测量证明，这三种化合物都是潜在的深紫外非线性光学材料。
