Calculation of ion scattering yields from simulated crystal surfaces: theory and application to melting and non-melting Al surfaces

We present a formalism for the calculation of medium-energy ion scattering yields from crystal surfaces that are simulated using the Monte Carlo or molecular-dynamics method. Input in the calculations is the interatomic potential of the atoms in the crystal and the ion-atom interaction potential. We have applied the formalism to calculate scattering yields from Al(111) and Al(110) surfaces. In these simulations the effective-medium theory is used to describe the interactions between the Al atoms. The results of the calculation are compared with experimental scattering yields. Excellent agreement is obtained at low temperatures, where both surfaces are ordered, as well as at temperatures close to the bulk melting point, where the Al(110) surface exhibits surface melting