We have studied the quasi-two-dimensional freezing and respective melting at the liquid/vapour interface of a dilute lead-in-gallium alloy (0.52 at. Pb) for the first time by XPS and AES spectroscopy at different temperatures below and above the transition temperature of 183.5 degreesC. Pb-rich wetting films of roughly 1 monolayer have been determined. At the onset of surface freezing (SF) the film thickness rises to a value of similar to2 monolayers and reaches a maximum of similar to4 monolayers of nearly pure Pb at similar to1 K below the SF temperature. These film characteristics are reproducible in different heating and cooling cycles. (C) 2004 Elsevier B.V. All rights reserved.
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