Short-range structural change in indium melt by Gaussian peaks decomposing of RDF

Liquid indium's structure was studied at 280, 390, 550, 650, and 750℃ respectively by using an elevated temperature X-ray diffractometer, and its radial distribution function (RDF) at different temperatures was decomposed into 4 Gaussian peaks in the range of 0.2-0.6 nm. Positions of the decomposed Gaussian peaks were compared with the nearest and the second nearest neighbor atomic distances, respectively. It is shown that the position of the first decomposed Gaussian peak is similar to the nearest neighbor atomic distance in liquid In at the corresponding temperature, and that of the third decomposed Gaussian peak is similar to the second nearest neighbor atomic distance. Moreover, the first and the third Gaussian peaks correspond to the first and the second atom shells of liquid In at the corresponding temperatures, respectively. Therefore, the position and the area of Gaussian peaks can represent the position and atom number of corresponding shells. Based on this result, short-range structural change in liquid In was studied. It was found that the first and the second shells are close to the referred atom, and the atom number at the shells decreases with the increasing temperature from 280 to 750℃. In different ranges of temperature, structural changes in the first and the second shells show different features.