THE SOLID-LIQUID SURFACE-TENSION AT A HELIUM CESIUM INTERFACE

The existence of a wetting transition for helium adsorbed on cesium pr ovides an experimental opportunity to investigate the solid-liquid sur face tension. We have extracted the temperature dependence of the soli d-liquid surface tension at the He-4/Cs interface from our earlier mea surements of the wetting temperature of pure He-4 on thin layers of ce sium overlaying gold. More recently we have measured the wetting tempe rature as a function of the He-3 concentration for He-3 - He-4 mixture s. An analysis of these experiments paralleling Andreev's investigatio n of the free surface reveals He-3 bound states at the helium/cesium i nterface.