论文标题
硅单晶的异常声子重变
Anomalous Phonon Renormalization in Single Crystal of Silicon
论文作者
论文摘要
硅（Si）单晶的一阶声子模式的温度依赖性是通过在4-623 K的宽温度范围内的拉曼散射确定的。我们的研究揭示了在低温区域中归因于SI异常膨胀的拉曼活性声子模式的异常红移。硅显示了低于120 K的负热膨胀，但是，在非常低的温度（即，在40 K以下检测到Si晶体的软化）也观察到了奇数行为。Si的这种特殊行为是由在低温下观察到的异常声子Anharmonitions描述的。
The temperature dependence of the first-order phonon mode of single crystal of Silicon (Si) is determined by Raman scattering in a broad temperature range of 4-623 K. Our studies reveal the anomalous red-shift of the Raman active phonon mode at temperature (~ 50 K) attributed to the anomalous expansion of Si in the low temperature region. Silicon shows negative thermal expansion below 120 K, however, odd behaviour is also observed at very low temperatures i.e., softening of the Si crystal is detected below 40 K. This peculiar behaviour of Si is described by the anomalous phonon anharmonicity observed at low temperature.
