Orbitals and Energies #
Note – these are listed in BINDING ENERGY
Ne 3s ≈ 290 eV
Ne 3p ≈ 213 eV
Ne 3d ≈ 87 eV
Common Overlaps for Kr 3d #
Mg 2s– Sn 4p – Ba 4d – Zn 3p – Au 4f
Theory and Background #
Noble gases do not tend to be analysed by XPS due to low reactivity, and volatility. There are a number of studies, however, on implanted ions in various substrates.
Experimental Advice #
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Data Analysis Guidance #
Studies of implanted noble gas ions found line broadening for all implanted gases, but line asymmetry was observed only for Ne 1s electrons implanted in Cu, Ag, and Au.[1]The authors concluded that this asymmetry was not due to core-hole lifetime effects (Auger broadening, etc.), but rather due to multiple implantation sites — in particular, the formation of small neon clusters inside the metal lattice. In such clusters, the screening of the Ne 1s core hole by conduction electrons is less effective than for isolated Ne atoms in substitutional sites. That reduced screening means some Ne atoms exhibit a higher apparent binding energy, producing the asymmetric tail at higher binding energy.
For Ar, Kr, and Xe, implantation produced predominantly substitutional sites (with only a few vacancies around them), so the spectra remained symmetric. But Ne is small and mobile, so clustering is favoured, giving rise to the observed asymmetry.
References #
- Citrin, P. H., and D. R. Hamann. “Measurement and calculation of polarization and potential-energy effects on core-electron binding energies in solids: X-ray photoemission of rare gases implanted in noble metals.” Physical Review B 10.12 (1974): 4948.
