Viscosity, Resistivity and Structural Chances of Bi₆₀Ga₄₀ Alloy Melt with Liquid-Liguid Phase Separation

摘要

The temperature dependence of viscosity of liquid Bi₆₀Ga₄₀ alloy has been measured using torsional oscillation viscosity measurement. The results show that the change of viscosity with temperature is distinctly discontinuous, which can be divided into three parts: the changes in high temperature region, mid-temperature region, as well as low temperature region. In these different regions, the structures of melt are distinct. The viscous flow activation energy E and group size v_m in low-temperature zone, namely, the liquid-liquid phase separation zone are larger than those in the medium-temperature and high-temperature zone zone, and E and v_m in the medium-temperature zone is the smallest. There is only low temperature anomalous point on the resistivity-temperature curve in liquid-liquid phase separation zone. The appearance of exothermic peaks on DSC curve during cooling process further proved the structure changes of melt in 893-923K. The liquid-liquid phase separation is naturally accompanied with structure change of melt in 535-563K, which is also reflected by the discontinuous change of viscosity and DSC analysis.