Work Function Study of Fe Adsorption on Fe (001) and (110)

The two-dimensional island growth of iron atoms adsorbed onto (001) and (110) surfaces of an iron single crystal was studied at various temperatures (110 K–R. T.) by measurement of the work function change. The (110) surface showed considerable decrease of the work function with increasing iron coverage (θ<0.5) and the curves of the change were interpreted in terms of the law, Δ φ∝√θ, on the island growth. The mean dipole moment of a single adatom was estimated to be 1 Debye at the low temperature (110 K). On the other hand, the (001) surface showed no work function change even at low temperature.