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A lab presented me with an elemental composition (mainly metals in char) derived from an XPS analyzer and mentioned that binding energies suggested a list of compounds (various oxides, sulfides and silicates etc). Is there a way to show the composition in terms of these compounds instead of just the elements? Only familiar in bucket chemistry (aka chem eng), these analyzers are a bit of a black box to me even after reading up on them.

Also, is analyzing the surface of a batch of tiny particles <<1 micron somewhat tricky to get reliable results?

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  • $\begingroup$ What do you mean by saying "in terms of these elements"? The xps analysis suggests these substances, there are other ways of determining the elemental composition of a particle mainly AAS (atomic absorption spectroscopy). $\endgroup$ – Avishai Barnoy May 2 '17 at 17:12
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    $\begingroup$ Having done work similar, the surface is often not representative of the bulk. $\endgroup$ – MaxW May 2 '17 at 17:22
  • $\begingroup$ The elements list shows for example: 3%Ni, 1%Fe, 2%Zn and so on and the accompanying annotation mentions compounds identified by binding energies are Fe2O3, FeS2, ZnO, ZnSO4 etc without showing the mass composition of these compounds. Is there any way of getting to compound percentages rather than element percentage? $\endgroup$ – user110084 May 2 '17 at 18:39
  • $\begingroup$ If the lab didn't break down the elemental fractions into compounds, then you probably can't readily estimate that either. If they also supplied processed, well-labelled spectra, then you may be able to get the proportion of FeS2 vs Fe2O3, for example, and work from there. But note that chemical state assessment in XPS is not 100% reliable - not all states are clearly resolved and uniquely identifiable. So I'd treat that compound list as a guide, not an assay. $\endgroup$ – AndyW May 3 '17 at 8:14
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This is a bit late, but I'll add an answer anyway. XPS is already a method that can be used for the speciation, so you should be able to differentiate between the different the different oxides of the same metal or metalloid. This is because the work function to eject an electron from a shell of the metal centre is dependent on its chemical environment.

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