Doublet Separations #

Cr 2p = 9.3 eV

Common Overlaps for Cr 2p #

Ag 3p – Te 3d – Ru 3s – Fr 4d – Hg 4p – W 4s – Cu LMM (Al Ka X-rays)

Auger Energies #

Note – these are listed in KINETIC ENERGY

Cr LMM ≈ 570 eV

Common Binding Energies – Cr 2p #

Theory and Background #

Chromium in particular oxidation states (most notably Cr(III) compounds, due to unpaired electrons) exhibits multiplet splitting. The 2p region exhibits broadening and asymmetry in a number of oxides, while the 3s region splits into two peaks in a manner indistinguishable when above or below the Curie temperature,[2] indicating that the ferromagnetic spin ordering does not influence this splitting. Cr(VI) is diamagnetic and therefore does not exhibit multiplet splitting. CrO2 is sometimes considered as a single pair of asymmetric peaks, due to being a conductive oxide[3] – however given the breadth of the peaks, and the paramagnetic [Ar]3d² configuration of Cr(IV) it is considered possible to be due to multiplet splitting rather than a asymmetric shake-up processes.[4]

Experimental Advice #

Chromium (VI) is known to photoreduce to tetra- and trivalent species under X-ray illumination.[5] This photoreduction can be greatly accelerated by certain charge neutralisation techniques – such as a dual neutraliser, and as such, care should be taken in selecting a neutralisation mode to minimise rapid sample damage.[6]

Data Analysis Guidance #

Fitting of Cr(III), much like any species with significant multiplet structure, can be a time-consuming task. Models developed from first-principles and standards can go a long way to help,[7] and recording your own data standards can help too.

Reference Datasets #

Coming soon

References #