Raman intensity profiles of folded longitudinal phonon modes in SiC polytypes
Raman intensity profiles of folded longitudinal phonon modes in SiC polytypes
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DOI：
10.1103/physrevb.62.16605
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发表时间：
2000-12-15
影响因子：
3.7
通讯作者：
Suemoto, T
中科院分区：
文献类型：
--
作者：
Nakashima, S;Harima, H;Suemoto, T
本文从实验和理论上研究了形成天然超晶格的4H-、6H-和21R-碳化硅多型体中折叠的纵向声子模的拉曼光谱分布。除了3C多型体中对应于区域中心声子模的模外，折叠的纵模的拉曼强度很弱。当考虑到立方和六方环境中键的拉曼极化率的差异时，根据键的极化率概念解释了这些模的强度分布。结果表明，键极化率模型可用于研究碳化硅中纵向折叠模和横向折叠模的拉曼光谱分布。
Raman spectral profiles of folded longitudinal phonon modes in 4H-, 6H-, and 21R-SiC polytypes which form natural superlattices have been studied experimentally and theoretically. The Raman intensity of the folded longitudinal modes is very weak except for the mode corresponding to a zone-center phonon mode in the 3C polytype. The intensity profiles of these modes are interpreted on the basis of;the bond polarizability concept when one takes into account difference of the bond Raman polarizability between the cubic and hexagonal environments. The agreement of the measured and calculated intensities indicates that the bond polarizability model can be applied to Raman spectral profiles of the longitudinal folded modes as well as transverse folded modes in SiC.