Raman scattering study of Ge and Sn compounds with type-I clathrate hydrate crystal structure
Raman scattering study of Ge and Sn compounds with type-I clathrate hydrate crystal structure
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DOI：
10.1103/physrevb.62.7157
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发表时间：
2000-09-15
影响因子：
3.7
通讯作者：
Kendziora, CA
中科院分区：
文献类型：
--
作者：
Nolas, GS;Kendziora, CA
在室温和 10 K 下研究了具有 I 型笼形晶体结构的多晶 Sr8Ga16Ge30、Eu8Ga16Ge30、Cs8Ga8Sn38 和 Cs8Zn4Sn37Ge5 的拉曼散射光谱。已经确定了这些化合物中的几种拉曼活性振动模式。 Ge 和 Sn 包合物的光谱相似，与 Ge 包合物相比，Sn 包合物的振动模式移至较低频率。偏振测量用于识别 A(g) 模式。在这些化合物中已经鉴定出与十四面体“笼”内的“客体”原子的“嘎嘎”振动相对应的两种拉曼活性模式的低频模式。该模式的频率位于这些化合物的声学声子分支内。将实验数据与理论预测进行比较。
Raman scattering spectra of polycrystalline Sr8Ga16Ge30, Eu8Ga16Ge30, Cs8Ga8Sn38, and Cs8Zn4Sn37Ge5, all with the type-I clathrate crystal structure, were studied at room temperature and 10 K. Several of the Raman-active vibrational modes in these compounds have been identified. The Ge and Sn clathrate spectra are similar, with the vibrational modes of the Sn clathrates shifting to lower frequencies as compared to Ge clathrates. Polarization measurements were used to identify the A(g) modes. The lower-frequency mode of the two Raman-active modes corresponding to the "rattling" vibrations of the "guest" atoms inside the tetrakaidecahedral "cages" have been identified in these compounds. This mode is at a frequency that is within the acoustic phonon branch of these compounds. The experimental data are compared to theoretical predictions.