I have a spectrum of Co(2p) (see attached picture) and would like to know the exact state of oxidation of Co. They are two main peaks at 785,6 eV for Co2P(3/2) and 800,9 eV for Co2P(1/2), and two peak satellite at 791,6 ev and 808,5 ev.
Maybe this article will help you http://onlinelibrary.wiley.com/doi/10.1002/sia.5933/abstract
best regards
These 6 factors could each contribute to different type of peaks in XPS spectra:
(A) Sharp peaks due to photoelectrons created within the first few atomic layers (elastically scattered).
(B) Multiples splitting (occurs when unfilled shells contain unpaired electrons).
(c) A broad structure due to electrons from deeper in the solid which are ineslastically scattered (reduced KE) forms the background.
(d) Satellites (shake-off and shake-up) are due to a sudden change in Coulombic potential as the photo ejected electron passes through the valence band.
(E) Plasmons which are created by collective excitations of the valence band either as Extrinsic Plasmon: excited as the energetic PE propagates through the solid after the photoelectric process or intrinsic Plasmon: screening response of the solid to the sudden creation of the core hole in one of its atom. The two kinds of Plasmon are indistinguishable.
(F) Auger peaks produced by x-rays (transitions from L to K shell: O KLL or C KLL).
See page 10 in the following document for a more detail description of the origin of the satellite peaks in XPS: https://public.wsu.edu/~scudiero/documents/571-XPS-Lecture2_003.pdf
Regarding your spectrum: the peak at 777.1eV is the satellite Ka3 from your Mg x-ray source at not from Co(0).
Thank you for disclosing important information. Let me think over it!
You may want to pay attention to the loss feature as well.
please see below.
https://xpssimplified.com/elements/cobalt.php
What about the peak at 777 and 792 eV ? are these the peaks of Cobalt? and if yes then in which oxidation states?
Christian Pettenkofer
Abdelali El Gaidoumi
The emission at 777 is Most probably the MgKa3 satellite from the xray source displacing the 785.6eV Emission by 8.4ev with a intensity of 8%. A similar emission may be hidden in the 791.6 2p3/2 shake up originating from the 2p1/2 main line. Some software packages have a routine called Satellite-Removal to suppress the Xray Satelliten from the source. The shown spectrum is recorded a little to short for a good background removal. After stellte subtraction a remaining emission at 778eV may hint to Co(0). A good idea may be to use monochromated XPS or recording the spektra again with Alka radiation (the Alka3 satellite has a shift of 9.8ev with 6.5% intensiv of the main line).
A suggested Reading is the introduction of the PHI XPS Handbook
Keep in mind also the Auger Emission line. If you used Al k-alpha x-rays to measure the spectrum, then the Co2p spectrum sits right on top of the CoLMM Auger lines. Actually, if you used Al k-alpha for this spectrum, the feature at 777 could be the CoLMM.
Bahram Roughani How does valence electron affect the photoelectron's energy?
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