LiGaF2(IO3)2:A mixed-metal gallium iodate-fluoride with large birefringence and wide band gap  

LiGaF2(IO3)2:同时展现出优异的双折射率和宽带隙的新型碘酸盐氟化物晶体

作　　者：Jin Chen Chun-Li Hu Jiang-Gao Mao 陈瑾;胡春丽;毛江高(State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences,Fuzhou,350002,China;University of the Chinese Academy of Sciences,Beijing,100039,China)

机构地区：[1]State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences,Fuzhou,350002,China [2]University of the Chinese Academy of Sciences,Beijing,100039,China

出　　处：《Science China Materials》2021年第2期400-407,共8页中国科学（材料科学（英文版）

基　　金：the National Natural Science Foundation of China(21875248,21921001,and 21975256);the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB20000000);the 100 Talents Project of Fujian Province。

摘　　要：The first mixed alkali-metal gallium iodate-fluoride,namely,LiGaF2(IO3)2,was successfully obtained under hydrothermal conditions.The structure of LiGaF2(IO3)2 features a novel two-dimensional(2D)[GaF2(IO3)2]layer composed of[Ga2F4(IO3)6]4 dimers further bridged by(IO3)groups.LiGaF2(IO3)2 exhibits a wide band gap of 4.33 eV,corresponding to the ultraviolet(UV)absorption edge of 230 nm.Calculations of linear optical property revealed that LiGaF2(IO3)2 has a remarkably large birefringence of 0.181@1064 nm and 0.206@532 nm,indicating that it is a potential birefringent material that could be used from visible to UV region.This study provides a new method for the future discovery of promising optical crystals.本文中,我们通过水热合成得到了首例混合碱金属镓碘酸盐氟化物,即LiGaF2(IO3)2,其晶体结构中包含了一种新型的二维阴离子层,即[GaF2(IO3)2]^-层.该二维层是由[Ga2F4(IO3)6]^4-二聚体通过碘酸根基团进一步桥连而得的.LiGaF2(IO3)2具有4.33 eV的宽带隙和230 nm的紫外截止边.线性光学性质计算结果表明其具有优异的双折射率,分别为0.186@1064 nm以及0.206@532 nm,这表明在可见到紫外波段,LiGaF2(IO3)2是潜在的双折射材料.理论计算表明,Ga-O/F八面体对该晶体的带隙和双折率都起到了增强的作用.这项工作对于未来探索性能优异的光学晶体提供了新方法.

关 键 词：metal iodate-fluoride birefringent material band gap enlargement theoretical calculations 

分 类 号：O734[理学—晶体学]