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D.C. four-probe method was used to investigate the temperature dependence of electrical resistivity of Sn-50wt%Sb melt. Anomalous changes observed on resistivity-temperature curves (ρ-T) suggest that temperature induced liquid-liquid structure transition (L-LST) might occur in Sn-50wt%Sb melt at hundreds of degrees above its liquidus, and the transition is reversible after the first heating cycle. An isothermal experiment based on ρ-T curve was conducted to further probe the effect of the L-LST on solidification morphologies. Results show that the size of the primary phase decreases and that the microstructure becomes finer when solidified from the melt experienced the irreversible L-LST. [ABSTRACT FROM AUTHOR]

The electrical resistivities of liquid Bi, Sb, and some of their alloys Pb-Bi, Pb-Sb have been investigated as a function of temperature, and the effect of heating-rate on the turning points of liquid Bi has also been investigated. Obvious and interesting hump phenomena are observed on resistivity-temperature curves of liquid Bi, Sb, and Pb-Bi, Pb-Sb alloys on heating at the temperature far above their liquidus. Moreover, the transition temperature of liquid Bi increases with heating-rate increasing, which shows that this kind of transition is in accordance with kinetic characteristics. However, comparing the heating curve with the cooling one, we found that the anomalous hump phenomenon is irreversible in liquid Bi, Sb, and Pb-Bi, Pb-Sb alloys. [ABSTRACT FROM AUTHOR]

The patterns of electrical resistivities versus temperature in large temperature range have been studied, using the D.C. four-probe method, for liquid Bi–In alloys (Bi–In(33 wt%), Bi–In(38 wt%), Bi–In(50.5 wt%), Bi–In(66 wt%)). The clear turning point of each resistivity–temperature curves of the liquid Bi–In alloys is observed at the temperature much above the melting point, in which temperature range the resistivity–temperature coefficient increases rapidly. Except for the turning temperature range, the resistivities of Bi–In alloys increase linearly with temperature. Because resistivity is sensitive to the structure, this experiment shows the structural transition in Bi–In melts at the temperature much higher than the liquidus. And it is suggested that there are different Bi–In short-range orderings in different Bi–In melts, so the resistivity–temperature curves have the turns at different temperatures and the resistivity–temperature coefficients are also different. [Copyright &y& Elsevier]