Structure and fragility of supercooled Ga-In melts

The melt structures and viscosities of Ga-In alloys were investigated by an x-ray diffractometer and a torsional oscillation viscometer. A difference in the temperature dependence of the viscosity between the supercooled and the superheated melt of Ga-In alloys was detected. Based on the concept of the melt fragility, we find that the fragility of the supercooled melt is larger than that of the superheated melt in this alloy system. Furthermore, the length of gallium covalent bond is larger in the supercooled melt. The cluster abruptly becomes much bigger, and the ordering degree increases obviously near the liquidus with decreasing temperature. This work provides a further understanding on the liquid-solid transition under the supercooled condition from the point of view of the melt dynamics. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4718437]