Pressure dependence of Raman phonons of some group IVA (C, Si, and Ge) elements
Pressure dependence of Raman phonons of some group IVA (C, Si, and Ge) elements
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某些 IVA（C、Si 和 Ge）元素拉曼声子的压力依赖性
DOI：
10.1016/0022-3697(91)90183-z
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发表时间：
1991
影响因子：
4
通讯作者：
Lin‐gun Liu
中科院分区：
文献类型：
--
作者：
T. Mernagh;Lin‐gun Liu
金刚石、硅和锗的拉曼光谱是在室温下、在金刚石砧池中、压力高达 180 kbar 的情况下测量的。使用金刚石砧本身的拉曼光谱作为压力校准标准的尝试没有成功，因为仅记录金刚石砧中心附近的高应力的实验困难。从硅和锗记录的拉曼光谱表明，在静压环境下，在压力分别略大于140和100 kbar的情况下，它们从立方金刚石结构转变为金属β-Sn结构。当压力释放时，硅和锗的金属相不会恢复到金刚石结构，而是在低于 70 kbar 的压力下形成亚稳态相。亚稳Si相的拉曼光谱与文献提出的体心立方结构一致。所提出的亚稳态Ge结构应具有多个拉曼带，但在本研究中仅观察到292 cm−1（在环境条件下）处的一个强拉曼带。根据这些元素的拉曼光谱计算了 C、Si 和 Ge 金刚石结构的体积模量，并与超声实验测定的结果进行了比较。
The Raman spectra of diamond, silicon and germanium were measured at room temperature for pressures up to 180 kbar in a diamond-anvil cell. Attempts to use the Raman spectra from the diamond anvils themselves as a pressure calibration standard were unsuccessful because of the experimental difficulty of recording only the high stress in the immediate vicinity of the centre of the diamond anvil.Raman spectra recorded from silicon and germanium showed that they change from the cubic diamond structure to the metallic β-Sn structure at pressures slightly greater than 140 and 100 kbar, respectively, under a hydrostatic environment. When the pressure is released the metallic phase of both silicon and germanium does not revert to the diamond structure but forms a metastable phase at pressures below 70 kbar. The Raman spectrum of the metastable Si phase is consistent with the body-centred cubic structure proposed in the literature. The proposed structure of metastable Ge should possess several Raman bands, yet only one strong Raman band at 292 cm−1(at ambient conditions) was observed in the present study. The bulk moduli of the diamond structures of C, Si and Ge were calculated from the Raman spectra of these elements and compared favorably with those determined by ultrasonic experiments.