Gong Xiangnan, Yan Ting, Li Jue, Liu Jie, Zou Hanjun, Zhang Bin, Wu Hong, Zhou Zizhen, Zhou Xiaoyuan
Analytical and Testing Center, Chongqing University Chongqing 401331 China
College of Physics, Chongqing University Chongqing 401331 China
RSC Adv. 2022 Nov 10;12(50):32262-32269. doi: 10.1039/d2ra06470g. eCollection 2022 Nov 9.
Tin sulfide (SnS), a IV-VI group layered compound, has attracted much attention because of its excellent thermoelectric properties along the crystallographic -axis. However, there are few reports on the identification of its in-plane orientation. We observe a strong anisotropy of the in-plane Raman signal in bulk SnS. With the help of calculations, the vibrational symmetry of each observed Raman mode in the cleaved (00)-plane is consistent with the experimental values. The angle-resolved polarized Raman spectroscopy, combined with electron backscattered diffraction technology, is utilized to systematically investigate the in-plane anisotropy of the phonon response and then determine the in-plane orientation. Furthermore, the temperature-dependent and laser-power-dependent Raman scattering analyses reveal that the adjacent layers in the SnS crystals show a relatively weak van der Waals interaction. These findings could provide much-needed experimental information for future applications related to the anisotropic transport properties of SnS single crystals.
硫化锡（SnS）是一种IV-VI族层状化合物，因其沿晶体学c轴具有优异的热电性能而备受关注。然而，关于其面内取向识别的报道较少。我们观察到块状SnS的面内拉曼信号具有很强的各向异性。借助计算，在解理的（00）面中每个观察到的拉曼模式的振动对称性与实验值一致。利用角分辨偏振拉曼光谱结合电子背散射衍射技术，系统地研究了声子响应的面内各向异性，进而确定面内取向。此外，温度和激光功率依赖的拉曼散射分析表明，SnS晶体中的相邻层表现出相对较弱的范德华相互作用。这些发现可为未来与SnS单晶各向异性输运性质相关的应用提供急需的实验信息。
