Outer core spectra of Cs and Rb on Mg surfaces

The authors report Cs5p and Rb4p spectra for these atoms adsorbed at various coverages on clean Mg surfaces. At low coverage, <or approximately=10 14 cm -2 , Cs exists on Mg part-ionised. The neutral configuration predominates at higher sub-monolayer coverages. The neutral Rb configuration exhibits a greater stability at low coverage than that of Cs. For both species, the spectrum of the first monolayer remains visible as second and higher layers build up and contribute spectral components resembling those of the pure bulk alkali metals.