Hi, i am currentyl fitting mno2 material into the peak at Mn 2p 3/2 and Mn 2p 1/2. in the right side of the peak, the tip highlighted in red is still not fit enough. is there any idea how to fit the top so that the black lines all matched the blue raw data lines?I already estimated the initial value and the fix it and then run the first itenery. after that i ticked of the fix button and let it run again. But it is still not fit enough.
Thank You very much for your kind assistance
The raw data up there looks like it has some artifact, maybe something from the detector? I don't think that's a convoluted component effect, so trying to fit that will probably not make it more meaningful.
Another question: if I look at the first two components on the high energy end, the left one looks wider than the next one. Is that a physical intention?
Hi Dr. Weippert, thank you for your answer. Yeah, the raw data has some kind of chipped peak (highlighted in red) and no matter how many iterations I ran, it still won't fit well enough.
Regarding your other question, do you mean the first two components on the left side peak (B.E 657 EV - 653 EV)? I am not sure if it is normal because I am quite new to XPS technique. I referenced a certain paper that stated The Mn 2p3/2 peak is split into three peaks at 643.3 eV, 642.0 eV and 640.6 eV, and the Mn 2p1/2 peak is also split into three peaks at 654.6 eV,653.5 eV and 651.9 eV, which correspond to Mn4+, Mn3+ and Mn2+
oxidation states. Therefore, I inputted the above peaks into the XPSpeak41 and run the itenary to fit the curve to the first picture that i posted before.
I wasn't so much talking about the positions, but the widths. These are determined mainly by the relaxation process of the electrons, so if you have metallic vs. ionic material, variations may happen, while when they are somewhat chemically similar, their width should also be close to identical.
Now back to the positions: at least for the oxides, they are not shifting that far apart: https://www.thermofisher.com/de/de/home/materials-science/learning-center/periodic-table/transition-metal/manganese.html
Particularly, by eyeball I don't see a satellite at 647 eV, so I would doubt the presence of significant amounts of Mn2+.
Thank You Dr. Weippert for your answer. Regarding the widht, It might be that the fitting parameter that i inputted into the software are not correct. Do you think it should be like this one that i attached in the files? Especially the (a) part in which the widht of each component are roughly the same?
No, these fits look very inconsistent. Just compare the Mn2+ "components" in panels b+d, they have completely different widths. Also, the panels are all labelled MnO2, so unless they used completely wrong samples, there should be no Mn2+ at all. I would not use whatever publication this is as a reference, basically everything about it looks fishy.
Check out the ThermoScientific learning center I linked above and the literature referenced therein.
Edit: I just saw at second glance that not even the coupling components are labelled correctly, they wrote Mn2p1/3, that doesn't exist.
Understood Dr. Weippert. Thank You for your guidance. I am still new to the XPS technique. Your comments really helped me better understand this technique.
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