Surface extended X-ray absorption fine structure methods were used to determine the adsorption geometry of K on Si(100)-(2 x 1) in the single-site regime at half-monolayer coverages. The results indicated that K was adsorbed at a low-symmetry dangling-bond site, with a K-Si bond length of 0.320nm. Also, normal incidence surface extended X-ray absorption fine structure data revealed K back-scatterers at 0.381nm. This was consistent with K adsorption at adjacent sites along the dimer rows.

R.Lindsay, H.Dürr, P.L.Wincott, I.Colera, B.C.Cowie, G.Thornton: Physical Review B, 1995, 51[16], 11140-3