X-ray diffraction and small-angle x-ray scattering measurements on expanded fluid selenium
X-ray diffraction and small-angle x-ray scattering measurements on expanded fluid selenium
复制标题
膨胀流体硒的 X 射线衍射和小角 X 射线散射测量
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
C. Li
中科院分区：
文献类型：
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作者：
M. Inui;T. Noda;K. Tamura;C. Li
为了研究膨胀流体硒中的电子-金属转变中的结构变化，在高温和高达1500巴的压力下进行了X射线衍射和小角X射线散射（SAXS）测量。X射线衍射研究结果表明，在金属流体中基本上保持了双配位结构。共价键在附近变短，金属特征开始增强。这些结果表明，链分子的局部结构随转变而变化。由于超导体向金属的转变发生在液-气临界点附近，因此研究临界密度涨落与相变的关系是很重要的。在400巴下的SAXS谱显示在大约以上出现宽峰，这可能表明在金属流体中具有约50 A的相关长度的密度波动。
To investigate the structural change in the semiconductor-to-metal transition in expanded fluid selenium, x-ray diffraction and small-angle x-ray scattering (SAXS) measurements at high temperatures and pressures up to and 1500 bar have been carried out. The results of the x-ray diffraction study show that the twofold-coordinated structure is largely preserved in the metallic fluid. The covalent bond becomes short at around , where the metallic character starts to be enhanced. These results suggest that the local structure of chain molecules changes with the transition. Since the semiconductor-to-metal transition occurs near the liquid - gas critical point, it is important to study how the critical density fluctuations are concerned with the transition. The SAXS spectra at 400 bar show that a broad peak appears at around above , which may suggest density fluctuations with a correlation length of about 50 A in the metallic fluid.