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第1楼2014/09/23
You cannot judge just by this narrow-spectrum. On the Nd3d peak there should be a double of 3d5 and 3d3.
If it is a metal Nd, Nd3d5 should be near 202eV BE and 3d3 at 205.2eV BE. But the peaks you have seems to be near 204eV indicating even Nd is existed it maybe in an Oxide form.
***There looks like a peak near 198eV BE too but it is almost no way for the Nd3d peak to shift to lower binding energy in Chemical form. Or unless you have some sample charging effect on your sample?
Going to next step if you want to "believe" the peak near 204eV is really Nd3d and looking at your spectrum this "peak" have an intensity of 0.05e+4 (peak to background). Then if you want to prove what you "believe" then you can look at Nd3p which is around 360eV BE. From standard spectra checking, if Nd is really presence, then Nd3p should have an intensity about half to Nd3d. So if you can see a peak at ~360eV BE and intensity is roughly like 0.025e+4 (peak to BG) then you can double confirm it is indeed the Nd being presence.
The peaks in your spectrum are really quite small, so it is indeed difficult to judge if such an element really presence or not. But with another small peaks in what so-called the same family peaks to come up, it can be a good proof for a presence of an element.
Hope you enjoy XPS~
摆度
第3楼2014/09/23
Maybe the concentration of Nb is really low. What atomic concentration % do you expect?
Usually we say XPS detection limit is 0.01 to 0.1AC%, but it also highly depending on the interested element. So we better use the higher limit meaning 0.1AC% as the line. So do you expect Nb concentration is >0.1AC%?
Like mentioned, please confirm with Nb3p peaks too. Many other factors can also affect you to really detect Nb or not, such as surface contamination on sample.
Your same is in powder or big piece of solid?
If it is powder, how do you prepare your sample?
摆度
第8楼2014/09/29
From O1s spectra, its difficult to see if seeing Metal-Oxide. Can you look at the survey spectrum at ~361eV Binding Energy because this is where Nb3p3 peak is. And from standard spectra I just check, its intensity maybe about half of Nb3d peak.
If you can see "some" peaks there you can have more proof if Nb really detect in your sample or not.
摆度
第10楼2014/09/30
You said the presence of Nb is "CONFIRMED".
I think you said that because you 'think' your sample surely have Nb. But for me as only looking at the XPS spectra, the presence of Nb seems uncertain to me. Like you said, the peaks acquired for Nb3d seems too small. Acquiring in bigger range for Nb3d like you said can be useful, because the right-hand-side peak is in doubt what exact is it. But after all, I still would try to look at the Nb3p peaks and if I can see it, then I will say it is "CONFIRMED".
Good luck~