Four new quaternary chalcogenides A2Ba7Sn4Q16 (A = Li, Na; Q = S, Se): syntheses, crystal structures determination, nonlinear optical performances investigation
Four new quaternary chalcogenides A2Ba7Sn4Q16 (A = Li, Na; Q = S, Se): syntheses, crystal structures determination, nonlinear optical performances investigation
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四种新型四元硫属化物 A2Ba7Sn4Q16（A = Li、Na；Q = S、Se）：合成、晶体结构测定、非线性光学性能研究
DOI：
10.1039/c7nj04288d
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发表时间：
2018-03-07
影响因子：
3.3
通讯作者：
Pan, Shilie
中科院分区：
文献类型：
--
作者：
Abudurusuli, Ailijiang;Wu, Kui;Pan, Shilie
在真空密封硅管中首次合成了四个新的四元硫属化合物A2Ba7Sn4Q16(A=Li，Na；Q=S，Se)。它们都属于非中心对称立方三维空间群，晶胞参数分别为14.807~15.4163 A和Z=4。有趣的是，它们的等位结构不同于以前报道的Na2BaSnQ4化合物的结构转变(从四方到三角)。在其结构中观察到，(Na/Ba)Q4和SnQ4单元通过共角交替连接，建立了一个三维(3D)骨架结构，电荷平衡的Ba离子位于隧道内，这与Na2BaSnS4中BaS8和SnS4单元互连形成的隧道内的Na原子不同。系统地研究了它们的光学性质(漫反射光谱、红外光谱和拉曼光谱)，结果表明它们的光学带隙在1.75-2.5 eV之间。此外，在2.09μm辐射下，标题化合物的倍频响应也比基准AgGaS_2提高了约0.1~0.5倍。
Four new quaternary chalcogenides A2Ba7Sn4Q16 (A = Li, Na; Q = S, Se) were successfully synthesized in vacuum-sealed silica tubes for the first time. All of them crystallize in the noncentrosymmetric (NCS) cubic I3d space group with the cell parameters ranging from 14.807 to 15.4163 A and Z = 4, respectively. Interestingly, their isostructures are different from the structural transformations (from tetragonal to trigonal) appearing in previously reported Na2BaSnQ4 compounds. As observed in their structures, (Na/Ba)Q4 and SnQ4 units alternately connect with each other by sharing corners to build a three-dimensional (3D) framework structure with charge-balanced Ba cations located within tunnels, which is different from the observation that the Na atoms located inside the tunnels formed by the interconnection of the BaS8 and SnS4 units in Na2BaSnS4. Optical properties (diffuse-reflection, IR, and Raman spectra) were also systematically studied and the results indicate that their optical bandgaps are in the range from 1.75 to 2.5 eV. Moreover, the second harmonic generation (SHG) responses of the title compounds were also measured to be about 0.1–0.5 times higher than that of benchmark AgGaS2 under 2.09 μm radiation.