Estimation of the temperature coefficient of surface tension of the interface between phases which form a eutectic

A study was conducted for the estimation of temperature coefficient of surface tension for the interface between eutectic pairs. The model of uniform surface layer of finite thickness was used to characterize the transition region between the phases. The variation of surface layer thickness with temperature occurs in different ways depending on the kind of phase transition. An equilibrium binary eutectic system A-B with the eutectic ratio of components, was also considered for the estimation. The system becomes single-phase as a result of contact melting and homogenization of the formed liquid, above the eutectic temperature. The surface layer, which plays the part of nucleus of a new phase, grows only at temperatures above the temperature of first-order phase transition such as eutectic temperature at which the new liquid phase becomes stable. It was assumed that the surface layer thickness is equal to that of monatomic layer and the solutions are regular.