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The surface energy and entropy of liquid Ga–Bi and Ga–Pb alloys have been studied by means of surface light scattering measurements at various compositions and temperatures between the respective eutectic and monotectic points. Analysis of these results using the Gibbs adsorption equation gives evidence for wetting and prewetting transitions in these alloys completely consistent with a tetra-point wetting scenario (Dietrich S and Schick M 1997 Surf. Sci. 382 178). Surface freezing transitions are observed for conditions near the liquidus curves. In view of their viscoelastic properties and their relation with the wetting film characteristics, we suggest a simple explanation for the observed surface freezing phenomena in terms of nucleation of strongly undercooled wetting films.

In situ grazing-incidence x-ray diffraction studies of reconstructed Au(111) electrodes in aqueous electrolyte solutions are presented, which reveal a significantly increased compression of the Au surface layer during Au electrodeposition as compared to Au(111) surfaces under ultrahigh vacuum conditions or in the Au-free electrolyte. The compression increases towards more negative potentials, reaching 5.3% at the most negative potentials studied. It may be explained within a simple thermodynamic model by a release of potential-induced surface stress.