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, r...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?℃.展开更多
The structure and dynamic viscosity of In 80 Cu 20 alloy melt in the temperature range from 600 ℃ to 1 000 ℃ were investigated by using a high temperature X ray diffractometer and a torsional oscillation viscometer....The structure and dynamic viscosity of In 80 Cu 20 alloy melt in the temperature range from 600 ℃ to 1 000 ℃ were investigated by using a high temperature X ray diffractometer and a torsional oscillation viscometer. The experiments show that there exist medium range order (MRO) structures in In 80 Cu 20 alloy melt in a low temperature range above liquidus. The MRO structures are weakened with increasing temperature and disappear when the temperature surpasses 800 ℃. The nearest interatomic distance r 1 and the coordination number N s of In 80 Cu 20 alloy melt decrease as temperature increases from 650 ℃ to 1 000 ℃. Thermal contraction of atom clusters can be found in the heating process. The viscosity of In 80 Cu 20 alloy melt drops as temperature increases and meets with the exponential relation. No sudden change in structure occurs in the measured temperature range. DSC curve of In 80 Cu 20 alloy during cooling process was measured. It is found that there is no noticeable variation of heat during cooling from 1 000 ℃ to 600 ℃, which testifies further that there is no sudden change in structure of In 80 Cu 20 alloy melt.展开更多
文摘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?℃.
文摘The structure and dynamic viscosity of In 80 Cu 20 alloy melt in the temperature range from 600 ℃ to 1 000 ℃ were investigated by using a high temperature X ray diffractometer and a torsional oscillation viscometer. The experiments show that there exist medium range order (MRO) structures in In 80 Cu 20 alloy melt in a low temperature range above liquidus. The MRO structures are weakened with increasing temperature and disappear when the temperature surpasses 800 ℃. The nearest interatomic distance r 1 and the coordination number N s of In 80 Cu 20 alloy melt decrease as temperature increases from 650 ℃ to 1 000 ℃. Thermal contraction of atom clusters can be found in the heating process. The viscosity of In 80 Cu 20 alloy melt drops as temperature increases and meets with the exponential relation. No sudden change in structure occurs in the measured temperature range. DSC curve of In 80 Cu 20 alloy during cooling process was measured. It is found that there is no noticeable variation of heat during cooling from 1 000 ℃ to 600 ℃, which testifies further that there is no sudden change in structure of In 80 Cu 20 alloy melt.
