Local structure of liquid Te studied by neutron diffraction and EXAFS
Local structure of liquid Te studied by neutron diffraction and EXAFS
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DOI：
10.1524/zpch.217.7.863.20397
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发表时间：
2003-01-01
影响因子：
2.5
通讯作者：
Ikemoto, H
中科院分区：
文献类型：
--
作者：
Endo, H;Maruyama, K;Ikemoto, H
对液体（1-）Te进行了中子衍射测量。在g(r)的第一个峰值之后的第一个最小值远高于零并充满了温度，而第二个峰值在高温下大幅减小并趋于平缓。结合EXAFS结果提供的结构信息，分析了g(r)的温度变化。g(r)对1-Te的曲线拟合预测两种不同的链间成分共存。第一个对应于3.2埃附近的短距离链间组分，第二个对应于3.8埃附近的长距离链间组分。高温3.2埃左右第一个最小值的充填明显与金属化有关。基于模型g(r)的EXAFS分析表明，为了拟合EXAFS信号的近程灵敏度区域的振荡频谱，需要在1-Te中负责金属传导的短距离链间分量（P2）和最近的链内分量（P1）。结果表明，1-Te的S-M转变是由短链分子组成的密集排列结构转变而来的。
Neutron diffraction measurements for liquid (1-) Te have been performed. The first minimum after the first peak of g(r) is well above zero and filled up with temperature, while the second peak diminishes substantially and flattens out at high temperature. The temperature variations of g(r) are analyzed combining the structural information available from our EXAFS results. The curve fitting of g(r) for 1-Te predicts that two different inter-chain components coexist. The first corresponds to the short-distance inter-chain component around 3.2 Angstrom and the second corresponds to the long-distance inter-chain component around 3.8 Angstrom. The filling of the first minimum around 3.2 Angstrom at high temperature is clearly related to the metallization. EXAFS analysis on the basis of the model g(r) indicates that the short-distance inter-chain component (P2) responsible for the metallic conduction in 1-Te as well as the nearest intra-chain component (P1) are required for fitting the oscillatory spectrum in the region of short-range sensitivity of the EXAFS signal. It is concluded that the S-M transition observed for 1-Te arises from the transformation to the densely packed configuration composed of shortened chain molecules.