Fig. 77: Reflectivity of the Ga/diamond(111) interface as a function of perpendicular momentum transfer Q (a). The solid curve is the best-fit reflectivity curve, obtained by Fourier transform of the electron density profile of (b). The dashed curve is a model calculation for a non-oscillatory density profile. The inset shows a schematic of the scattering geometry. Figure 77(b) shows the best-fit model of the oscillatory in-plane averaged electron density profile as a function of the distance z along the interface normal. In (c), a structural model consistent with the above density profile is shown. Carbon atoms are illustrated by small circles and Ga atoms by larger ones; Ga2 dimers are represented by two atoms connected by a line.