Azimuthal dependence of reflection high resolution electron energy loss of Si(111)(2×1)

Abstract High Resolution Electron Energy Loss Spectroscopy has been used, with low energy of the primary beam and azimuthal resolution, to study the anisotropy of surface dielectric properties of Si(111)(2 × 1), in the range of the surface electronic excitations. By eliminating the effect of the kinematic prefactor, we are able to obtain from the data the surface Loss Function. Its dependence on q ∥ and ω is discussed in term of a model of surface dielectric function.