Atomic Structure and Sound Wave in Liguid Alloys incorporating with Metal-Nonmetal Transition

观察到液碲及其合金的电子性质、热和结构因素对温度有很大的依赖性。这些异常是由于从非金属态到金属态的转变，结合了系统中键合的重组。用基于逐渐转变的肖特基型比热完全解释了液态Se-Te和IIIb-Te合金的大比热。利用这些热力学数据，可以在原子尺度上分析这些体系的结构因素。特别地，液态Se-Te合金结构函数的温度依赖关系可以用从二元坐标分量（非金属）到三重坐标分量（金属）的逐渐转变来解释。这些体系的声速可压缩性表现出较大的超额值，用一种洛雷兹曲线表示。我们还发现，这个超额值在现象学上与金属和非金属状态之间的体积差（V_M-V_N）和金属分数随压力的分化的乘积成正比。在转变温度下，体系的暗粘度与剪切粘度之比也有最小值，这种转变属于高阶转变。

A large temerature dependence of the electronic properties, heats and structure factors in liquid tellurium and their alloys has been observed. These anomalies are due to the transition from non-metallic to metallic state incorporating to the recombination of bonding in the system. The large specific heats in liquid Se-Te and IIIb-Te alloys are fully explained in terms of Schottky-sype specific heat based on a gradual transition. Using this thermodynamic data, the structure factors of these systems can be analysed in the atomic scale. In particular, the temperature dependence of measured structural functions of liquid Se-Te alloys could be explained by a gradual transition from two-fold coordinate component (non-metallic) to the three-fold one (metallic)The compressibilities obtained from the sound velocity for these system show a large excess value which is expressed by a kind of lorezian curve. We also found that this excess value is phenomenologically propotional to a product of volume difference (V_M-V_N) between metallic and nonmetallic state and the differentiation of the metallic fraction with the pressure. The ration of the dulk viscosity and the shear viscosity of these system also shows a minimum at the transition temperatureIn conclusion this kind of transition is classified a higher order transition.