Electron Momentum Distribution of Liquid Metals by High Resolution Compton Scattering

本研究项目的目的是利用安装在KEK-PF和KEK-AR的高分辨率康普顿散射光谱仪研究简单液态金属和Li-Ga等非简单液态金属的电子动量密度。利用KEK-PF康普顿光谱仪对液态碱金属进行了研究，其动量分辨率为0.09原子单位，是目前世界上最高的。在Li和Na中熔化后，Compton轮廓的变化表现为轮廓形状的变窄。与纯金属相比，液态锂钠合金中费米动量的巨大模糊应该引起注意。采用KEK-AR新建成的康普顿光谱仪，在入射能量为60 keV时，动量分辨率为0.12原子单位，对液态锂镓合金进行了研究。与碱金属相比，纯Ga的康普顿谱变化在熔化后有所增加。这表明Ga的费米动量在熔化时增加。没有注意到Li_0._9Ga_0液相康普顿谱线的变化。_1合金与液态Ga casa相似。没有观察到费米动量的明显减少。在理论方面，利用拟势理论研究了InSb由金刚石型结构向nacl型结构相变对动量分布的影响。

The purpose of this research project is to study the electron momentum density of simple liquid metals and non-simple liquid metals such as Li-Ga using high resolution Compton scattering spectrometer installed at KEK-PF and KEK-AR.Liquid alkalline metals were studied using Compton spectrometer at KEK-PF which have the momentum resolution of 0.09 atomic unit, the highest resolution in the world. Changes of Compton plofiles upon melting in Li and Na showed the narrowing in the shape of the profile. The great blurring of the Fermi momentum in liquid Li-Na alloy compared to that in pure metals should be noticed.Liquid Li-Ga alloy were investigated using a new Compton spectrometer constructed newly at KEK-AR with the momentum resolution of 0.12 atomic unit at the incident energy of 60 keV. The Compton profile change of pure Ga showed an increase upon melting in contrast to alkaline metals. This suggest that the Fermi momentum of Ga increases upon melting. It is no be noticed that the change of the Compton profile of liquid Li_0._9Ga_0._1 alloy was similar to liquid Ga casa. No noticeable decrease of the Fermi momentum has been observed.From the theorerical side, the effeects of phase-transition from diamond-type to NaCL-type structure of InSb on momentum disribution have been studied in terms of pseudo-potetial theory.