Thermal contraction phenomenon of cluster structure of indium melt

摘要

The structure of liquid indium was studied at 280, 390, 550, 650, 750?℃, respectively, by using an elevated temperature X ray diffractometer. The diffraction intensity, structure factor, pair distribution function, radial distribution function, nearest interatomic distance and coordination number were obtained. The results show that the structure of In melt can be approximately described by the random closed packed hard sphere model with hard sphere diameter d =2.86??, packing density η =0.45. The cluster structure of In melt transforms from quasi face centered cubic lattice into random closed packed structure above melting point. It has been found that the nearest interatomic distance r 1 and coordination number N s decrease with increasing temperature from 280?℃ to 750?℃, r 1 decreases from 3.25?? to 3.18?? and N s decreases from 12.771 to 6.648, and thermal contraction phenomenon of atom cluster occurs. Thermal contraction of In melt cluster is not homogeneous in whole measured temperature range. The sudden transformation and the biggest contraction have been found in the range of 390～550?℃.