Thermal contraction phenomenon of
cluster structure of indium melt
cluster structure of indium melt
(1. The Key Laboratory of Liquid Structure and Heredity of Materials，
Ministry of Education，Shandong University，Ji′nan 250061，China；
2. Mechanical Engineering Department,
Shandong University of Technology, Zibo 255000, China；
3. Shandong Dacheng Pesticide Co. Ltd., Zibo 255000, China)
Ministry of Education，Shandong University，Ji′nan 250061，China；
2. Mechanical Engineering Department,
Shandong University of Technology, Zibo 255000, China；
3. Shandong Dacheng Pesticide Co. Ltd., Zibo 255000, China)
Abstract: 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 coordinati on 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 r1 and coordination number Ns decrease with increasing temperature from 280℃ to 750℃, r1 decreases from 3.25 to 3.18 and Ns 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℃.
Key words: melt; cluster structure; thermal contraction; X-ray diffraction