Structural characterization of submonolayer C/Al(111)

We report on the adsorption of atomic C in submonolayer coverages on the Al(111) surface. The local order at the surface is studied for different thermal treatments by means of full-heimispherical X-ray photoelectron diffraction. Deposition at room temperature results in disordered C adsorption while an ordering process takes place after annealing above 475 K. We depict the structure of the annealed C-rich phase. The C1s diffraction patterns are interpreted by comparison with single scattering cluster calculations. The results are discussed with respect to both previous theoretical and experimental work.