  Surface sensitive x-ray scattering techniques with atomic scale resolution
are employed to investigate the microscopic structure of the surface of three
classes of liquid binary alloys: (i) Surface segregation in partly miscible
binary alloys as predicted by the Gibbs adsorption rule is investigated for
Ga-In. The first layer consists of a supercooled In monolayer and the bulk
composition is reached after about two atomic diameters. (ii) The Ga-Bi system
displays a wetting transition at a characteristic temperature T_w~220 C. The
transition from a Bi monolayer on Ga below T_w to a thick Bi-rich wetting film
above T_w is studied. (iii) The effect of attractive interactions between the
two components of a binary alloy on the surface structure is investigated for
two Hg-Au alloys.
