Band effects on inelastic scattering of low-energy ions from metallic and ionic surfaces: A formalism beyond the adiabatic molecular-orbitals calculation

GARCIA E.; E.C. GOLDBERG

PHYSICAL REVIEW B - CONDENSED MATTER AND MATERIALS PHYSICS

The American Physical Society

Año: 1998 vol. 57 p. 6672 - 6684

0163-1829

Charge exchange and inelastic excitation processes have been analyzed in the scattering of low-energy He1from metallic and ionic surfaces. An Anderson-like Hamiltonian is proposed, where the parameters are definedtaking into account the electronic band structure of the surface as well as the atomic nature of the interactionbetween the projectile and the target atoms. The time-dependent collisional process is solved by using aGreen-function formalism, which allows us to calculate not only the charge-state probabilities but also theone-electron interband excitations in the solid. Competitive effects of the hybridizations among the localizedstate at the projectile site and the localized and extended surface states are contemplated. In this way we canexplain the observed energy dependences of the neutralization probability, as well as the occurrence of energylossprocesses due to the excitation of valence and core surface electrons induced by the collision.