Wetting and prewetting transitions in Ga-Pb alloys

This paper summarizes previous work on wetting and adsorption transitions in the Ga-Pb system. It describes a model of these transitions which is based on the regular solution approximation in conjunction with nearest neighbor interactions. It also reviews several recent novel experimental results obtained in Ga-Pb, including: (a) evidence that complete wetting prevails in Ga-Pb alloys within the domain of liquid-liquid coexistence; (b) a demonstration that the thickness of Pb at the surface of Ga diverges logarithmically as liquid-liquid coexistence is approached, as expected for metallic systems characterized by short-range interactions, and (c) studies of adsorption transitions by two complementary experimental approaches which map out the extension of the prewetting line and provide estimates of the prewetting critical point and the wetting temperature.