Sub-picosecond dynamics in liquid Si
Sub-picosecond dynamics in liquid Si
复制标题
液态硅中的亚皮秒动力学
DOI：
10.1088/0953-8984/15/40/l03
复制
发表时间：
2003
期刊：
影响因子：
--
通讯作者：
A. Baron
中科院分区：
文献类型：
--
作者：
S. Hosokawa;W. Pilgrim;Y. Kawakita;K. Ohshima;S. Takeda;D. Ishikawa;S. Tsutsui;Yoshikazu Tanaka;A. Baron
我们是第一个利用高分辨率非弹性 X 射线散射成功测量接近熔化的液态硅的动态结构因子 S(Q,ω) 的团队。光谱清楚地证明了熔体中存在传播的短波长模式，其 Q-ω 关系与其他液态金属系统中的关系类似。在结构因子最大值附近观察到准弹性线形状随着 Q 的增加而发生的特定变化。这一观察结果与金属到绝缘体转变附近亚皮秒时间尺度上原子关联的开始有关。以前仅在具有增加共价特性的金属系统的计算机模拟中进行了此类观察。我们的数据为这些超短密度相关性提供了第一个实验证据。
We are the first group to succeed in measuring the dynamic structure factor S(Q,ω) of liquid Si close to melting using high-resolution inelastic x-ray scattering. The spectra clearly demonstrate the existence of propagating short wavelength modes in the melt with a Q–ω relation similar to those in other liquid metal systems. A specific variation of the quasi-elastic line shape with increasing Q is observed close to the structure factor maximum. This observation is related to the onset of atomic correlations on the sub-picosecond timescale in the vicinity of a metal-to-insulator transition. Such observations have been made previously only in computer simulations of metallic systems with increasing covalent character. Our data provide the first experimental evidence for these ultrashort density correlations.