Sn-Bi合金熔体可逆液-液结构转变的研究

Reversibility of liquid-liquid transition in Sn-Bi alloys

本文采用直流四电极电阻法研究了Sn-Bi系合金熔体在连续几轮的升降温过程中电阻率随温度的变化规律.结果表明,Sn-Bi合金熔体在连续几轮的升降温过程都出现了电阻率随温度的异常变化.由于电阻率是结构敏感物理参数之一,电阻率随温度的异常变化间接表明合金熔体发生了温度诱导的液态结构转变,而且转变具有一定的可逆性.对比纯锡和纯铋的电阻率实验结果,可以认为结构转变的可逆性主要与合金中Sn的有关.

Using D. C. four-probe method, temperature dependence of electrical resistivity of Sn-Bi alloys has been investigated on heating and cooling process in several experimental cycles. The results show that there are clear turning points both on heating and cooling process in several experimental cycles. Since resistivity is one of the physical properties sensitive to structures, it is suggested that there is a reversible temperature-induced liquid-liquid structure change in Sn-Bi melts. Compared with the experimental results of pure Sn and Bi, similax reversible change is also observed in liquid Sn. It is assumed that Sn plays an important role in the reversible liquid-liquid transition.