Surface properties of alkali-metal alloys

Abstract
The surface energies and work functions of the disordered binary alloys of alkali metals are calculated using the density functional formalism and the variational principle for the energy. Vegard's law for the volumes is assumed. To calculate the structure-dependent pseudopotential contribution the virtual-crystal approximation and the linear relation between the Wigner-Seitz radius and the core radius of the Ashcroft model potential is used. The calculated variation of the work function against the concentration of the constituents is in good agreement with the measurements for Na-K, K-Rb and Rb-Cs systems.