Dear Colleagues,
If I want to get the binding energy of each electron of an Atom, it it possible to get?
For example, I am getting BE of 3S electron of Cu to be around 960 eV. But, I want to get the BE of 1S electrons.
Please suggest, how to get this.
Thanks and Regards
N Das
Well, your incident x-ray energy must be bigger than your output energy. This would be available at a synchrotron source so you could ask at the XPS beamline of htese and apply for beamtime.
However: what information do you hope to gather from those low electrons that are not accessible from the higher shells? Do you have a certain piece of literature you want to compare with?
Respected Jürgen Weippert,
Thanks for your valuable reply.
My query is regarding the experimental verification of the energy of the electrons in different states of an atom.
I don't know, if there is any other method to get the experimental evidence of electronic states of an atom.
Thanks and Regards
N Das
If that's your goal, I don't think there's any way around going to a synchrotron.
Respected Jürgen Weippert,
Thanks for your valuable reply.
Regards
N Das
What about Auger electron spectroscopy?
https://en.wikipedia.org/wiki/Auger_electron_spectroscopy
What about X-ray fluorescence?
What about EXAFS?
I do not have deep enough knowldge in these but the experts might help
Gyorgy Banhegyi
Auger could actually be an option, if you have an electron source with enough energy. Most standard setups aren't built for such high energies, I believe though.
XRF and EXAFS would also be synchrotron based.
Dear Jürgen Weippert , can you please give me a clear idea of the energy of the X-Ray used for XPS?
Regards
N Das
According to the Scofield cross sections,
https://www.osti.gov/biblio/4545040
Cu1s would require at least 11.6keV in order to be ionized. In reality, it might deviate from that number to some extent.
So you would have to find a synchrotron whose XPS beamline has a monochromator which goes to energies of this height which is pretty rare, I suppose. However, when you write a proposal for that, you will have to give more reason for your interest thatn the one sentence you stated above, just saying "I want to see it" will definitely not be enough.
Respected Jürgen Weippert,
I get nice ideas from you. Please give some ideas about the energy of X rays normally used in XPS analysis in Universities. I am new in this field of XPS analysis.
Regards
N Das
OK, normal X-Ray sources for XPS are Mg-Ka and Al-Ka, so sources with
Respected Jürgen Weippert,
Sir,
Thanks a lot for your kind discussion.
Regards
N Das
Dear Nityanand,
As mentioned by Jürgen XPS are usually defined s Photoelectron spectroscopy (PES) with excitation energies of up to 1500 eV, typically Al K alpha (1487 eV) and Mg K alpha sources . Above 2000 eV is defined as HAXPES, HArd X-ray PES. With such setups you can measure with Ag L alpha sources of about 2984 eV excitation energy, Cr K alpha (about 5400 eV), Cu K alpha (8046 eV) and Ga L alpha (about 9200 eV) or using a synchrotron with a beamline dedicated for HAXPES measurements, as normal XPS beamlines does not go up that high in energy or have analyzers that are capable of measuring such high kinetic energies that usually is the result of high photon energy excitation sources (except your C1s measurement that will have quite low kinetic energy due to the high binding energy of the core level).
For Cu 1s the tabulated energy is 8979 eV in the X-ray data booklet (https://xdb.lbl.gov/), hence you would need Ga excitation or a synchrotron that has dedicated HAXPES setups. There are several HAXPES beamlines around the world. See table 1 in this review of a complete list (from 2020): https://doi.org/10.1088/1361-648X/abeacd. One HAXPES beamline is the BL47XU in Spring-8. On their home page they display a Cu1s spectrum: http://www.spring8.or.jp/wkg/BL47XU/instrument/lang/INS-0000001384/instrument_summary_view.
Note that the cross section for deeper lying levels is not the same as for general XPS. So measurements it might take some time to record such spectra. The life time is also much shorter so the broadening of the spectrum will be larger than for shallower core levels.
Dependent on the information needed from this core level it would also be possible to apply other techniques, e.g. x-ray spectroscopy.
Best regards,
John
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