Scandium #
Orbitals and Energies #
Note – these are listed in BINDING ENERGY
Sc 2p ≈ 399 eV
Sc 2s ≈ 500 eV
Sc 3s ≈ 54 eV
Sc 3p ≈ 32 eV
Doublet Separations #
Sc 2p = 4.8 eV
Common Overlaps for Sc 2p #
N 1s – Yb 4p – Tb 4s – Ta 4p – Cd 3d – Tl 4d
Common Binding Energies – Sc 2p #
Theory and Background #
Scandium exhibits more classical behaviour in XPS, compared the the other first row transition metals. With Coster-Kronig transitions energetically unfavourable, and a lack of unpaired valence electrons results in no asymmetric peak broadening, or multiplet splitting – both features of first row TM XPS.
There is, however, significant peak asymmetry for Sc metal, owing to the high degree of electron density around the Fermi energy.
Experimental Advice #
Scandium overlaps significantly with N 1s – and as such, recording the Sc 2s as well as the Sc 2p will allow a secondary check in the event of significant amounts of both elements.
Data Analysis Guidance #
The main oxygen peak for Sc2O3 lies at 529.7 eV.
A hydrated/hydroxide species may lie at 531.8 eV. (1)
Fitting of native oxide overlayers may require use of a suboxide feature at around 400.5 eV.
References #
- Biesinger, Mark C., et al. “Resolving surface chemical states in XPS analysis of first row transition metals, oxides and hydroxides: Sc, Ti, V, Cu and Zn.” Applied surface science 257.3 (2010): 887-898. Read it online here.
- Zimina, Anna, Aline Léon, and Ralph Steininger. “Chemical bonding effects in Sc compounds studied using X-ray absorption and X-ray photoelectron spectroscopies.” Physical Chemistry Chemical Physics 26.3 (2024): 2613-2621. Read it online here.
