Size effect on surface tension of liquid binary alloy droplets

A simple model for size-dependent surface tension of liquid binary alloy droplets has been established based on Bulter’s equation and our model for size-dependent surface tension of pure liquid component. As an example, the surface tension of liquid Bi–Sn alloy droplets are calculated and discussed. The results show that as the size of the liquid alloy droplets decreases, the corresponding surface tension decreases. The component with lower surface tension is enriched in the surface layer at all times while relatively more another component with higher surface tension appear in the surface region when the size decreases. The effect of decreasing size on liquid alloy surface tension is like that of increasing temperature. When size is larger than about 12 nm, the size effect is small and negligible.

► We model the size-dependent surface tension of liquid binary alloy droplets.
► As the size of the liquid alloy droplets decreases, the surface tension decreases.
► The component with lower surface tension is enriched in the surface layer.
► More component with higher surface tension appears in the surface as size decreases.