Ultrasonic studies of ionic relaxation process for disordered systems with high density of conduction electrons.

本项目的目的是通过测量超声速度和衰减来研究具有高密度传导电子的无序系统中的密度和浓度涨落以及原子的驰豫过程。测量系统采用了Matec 7700脉冲调制器和接收器。室温下测得的液体水和乙醇中的速度和衰减系数与文献中的数据吻合较好。还对液态过渡金属的可压缩性进行了理论计算，它与实验上可获得的声速密切相关。硬球模型和单组分等离子体模型的计算结果令人满意。对液态Hg-In合金的剪切粘度进行了测量，在其等温线上发现了约5at%In的异常。这表明最近由本研究小组发现的液态汞合金中存在高阶关联函数效应的额外证据。综述了液态金属中超声衰减研究的实验情况。人们发现，到目前为止，他们实验的精确度还是相当差的。因此，以更高的精度继续研究这一项目是极其重要的。通过这些实验，可以进一步了解具有高密度导电电子的无序系统中的密度、浓度涨落和原子弛豫过程。

The purpose of this project is to investigate the density and concentration fluctuation and the atomic relaxation process in disordered systems with high density of conduction electrons by performing measurements of ultrasonic velocities and attenuations. The Matec 7700 pulse modulator and receiver was employed in the measuring system. The measured velocities and attenuation coefficients in liquid water and ethyl alcohol at room temperature were in good agreement with data in the literature. Theoretical calculations were also performed for the compressibility of liquid transition metals, which is closely related to experimentally obtainable velocities of sound. The calculated results due to the hard sphere model and the one component plasma model were satisfactory. Measurements were performed for the shear viscosity of liquid Hg-In alloys; anomalies were found around 5 at% In in its isotherms. This indicates the additional evidence for higher order correlation function effects in liquid Hg alloys, which have been found recently by present researcher's group. The review was given for experimental situations of study of ultrasonic attenuations in liquid metals. It was found that still now accuracies of their experiments are rather poor. Therefore it is extremely important to continue studies of this project with improved accuracies. By such experiments further understanding can be obtained about the density and concentration fluctuation and atomic relaxation process in disordered systems with high density of conduction electrons.