HAMAKER CONSTANT CALCULATIONS AND SURFACE MELTING OF METALS

Surface melting is strongly influenced by the interaction between the solid-liquid interface and the liquid-vapor interface. Electromagnetic dispersion forces yield a potential of the form H/l2, where l is the distance of the interfaces (thickness of the quasi-liquid film) and H is the appropriate Hamaker constant. We have adopted the well-known treatment of dispersion forces of Lifshitz et al., where the conductivities of the solid and of the liquid are the primary quantities for the calculation of the Hamaker constant of metals. From the known dielectric functions, numerical values for H are obtained for Pb, Al, Au, Bi and Ge, and are discussed in connection with recent experimental data on surface melting, particularly of Pb(110) and Al(110).