Doublet Separations #

Al 2p = 0.44 eV

Common Overlaps for Al 2p #

Br 3d – Pt 4f – Cu 3p – Cr 3s – Ru 4s – Cs 4d – In 4p

Common Overlaps for Al 2s #

Nd 4d – Cu 3s – Pm 4d – In 4s – Ge 3p – I 4p

Auger Energies #

Note – these are listed in KINETIC ENERGY

Al KLL ≈ 1390 eV

Common Binding Energies – Al 2p #

Theory and Background #

Al metal with small oxide overlayer XPS spectra of Al 2p and Al 2s region showing plasmon structure

Aluminium metal exhibits significant plasmon structure in its XPS spectra, and as such may be tricky should the correct energy window not be selected.

Experimental Advice #

When analysing aluminium, it is often sensible to collect an extended region to the higher binding energy side, in order to capture any plasmons and enable accurate background modelling.

Data Analysis Guidance #

Whilst it is commonplace to fit the sharp metallic doublet as a pair of peaks, and the alumina overlayer as a single voight-type convolution (due to the small doublet separation – 0.44 eV – relative to the broader oxide peaks for Al 2p), it is nonetheless good practice to fit every species as a doublet – particularly when deconvoluting multiple species.

Whilst this no doubt gives a good approximation for native oxides, and determining overlayer thicknesses – decoupling of chemical species surely benefits from a thorough treatment of the spin-orbit doublet in order to minimise errors in fitting shoulders and broadenings – such as in the cited example studying Al-grafted overlayers onto a silica interface from Parlett et al.

Reference Datasets #

Coming soon

References #