RESUMO
Complementary but independent medium-energy and low-energy ion scattering studies of the (0001) surfaces of V(2)O(3) films grown on Pd(111), Au(111) and Cu(3)Au(100) reveal a reconstructed full O(3)-layer termination creating a VO(2) surface trilayer. This structure is fully consistent with previous calculations based on thermodynamic equilibrium at the surface during growth, but contrasts with previous suggestions that the surface termination comprises a complete monolayer of vanadyl (V=O) species.
RESUMO
The energy spectrum associated with scattering of 100 keV H+ ions from the outermost few atomic layers of Cu(111) in different scattering geometries provides direct evidence of trajectory-dependent electronic energy loss. Theoretical simulations, combining standard Monte Carlo calculations of the elastic scattering trajectories with coupled-channel calculations to describe inner-shell ionization and excitation as a function of impact parameter, reproduce the effects well and provide a means for far more complete analysis of medium-energy ion scattering data.