Carbon on platinum: Work function changes caused by atomic carbon and by two-dimensional graphite islands

Carbon monoxide thermally dissociates in the kinked areas of a rounded Pt single crystal. The created C atoms cause a work function increase (Δφ = + 0.04 eV ({430}) to + 0.14 eV ({210}); experimental error in Δφ: ± 0.02 eV), which appears to depend linearly on the areas' kink densities. The surface dipole moment, μ(C/Pt), is roughly 0.1 ± 0.02 D. Beginning at about 850 K, C atoms form 2D graphite islands. These islands cause a work function decrease (Δφ = −1.58 eV ({210})).