Measurements were made of the surface tension of molten tin-germanium alloys of all concentrations in the temperature range 300–1200°C.
It is shown that, at certain temperatures, the σ-concentration isotherm has a minimum. A minimum in the σ-composition isotherms of systems free from chemical compounds would be expected to occur at sufficiently large positive deviations in the activity of the components from ideality.
A study was made of the wetting of germanium single crystals [(111) plane] by tin and Sn-Ge alloys under the conditions of equilibrium between the phases in contact and in the absence of such equilibrium. The angle of contact of liquid germanium on solid germanium under equilibrium conditions was determined.
The interfacial energy is controlled by the action of two factors: the difference in the properties of the phases in contact and the interaction between the phases (the state of nonequilibrium of the system). In systems where the liquid phase possesses a large solubility for the solid phase, the interfacial energy under equilibrium conditions may be less than that under nonequilibrium conditions.