Welcome to part 3 of our fundamentals of XPS for Beginners course. In this section, we will discuss the origin of doublet peaks and look at how we can model these and use them to our advantage.
1: If a doublet peak is determined to have an area ratio of 3:2, determine which orbital this must have come from (remember multiplicity = 2J+1)
2: Which of the following will have a larger doublet separation?
- Pt 4f v Pt 3d?
- Ti 2p v Cu 2p
- Cs 3d v Cs 4p
3: Assuming no final-state effects, if the FWHM of an In 3d5/2 peak is determined to be 1.2 eV, what should the FWHM of the In 3d3/2 peak be?
4: If you were to see an O 1s spectra like the one in figure 1, what do you think the reason might be?
In section four, we jump into a topic which is often not explored as much as it should be – the origin of the XPS background, how we model it and what it can tell us about our sample.