Hello all, I am analyzing EXAFS of some rare earth systems. It is known that there are multielectron transitions in these systems. So, I want to know how to subtract multielectron process contribution generally and if ATHENA has a feature to do this. Thank you very much. ZM
On Tuesday 12 July 2005 11:18, QY ZML wrote:
I am analyzing EXAFS of some rare earth systems. It is known that there are multielectron transitions in these systems. So, I want to know how to subtract multielectron process contribution generally and if ATHENA has a feature to do this. Thank you very much.
Athena does not currently have a feature for doing this. Drat! I would be willing to implement something empirical for doing this. I would like to see a discussion here on the mailing list of the merits of different approaches. Since I have never given this very much thought, I am not with any strong opinions for how it should (or should not) be done. But I can certainly consider implementing it. B -- Bruce Ravel ----------------------------------- bravel@anl.gov -or- ravel@phys.washington.edu *** My cell phone number has changed. Please ask if you need the new number Environmental Research Division, Building 203, Room E-165 Argonne National Laboratory phone and voice mail: (1) 630 252 5033 Argonne IL 60439, USA fax: (1) 630 252 9793 My homepage: http://feff.phys.washington.edu/~ravel EXAFS software: http://feff.phys.washington.edu/~ravel/software/exafs/
Dear Bruce An example of treating atomic absorption background including large multielectron features in L edge spectra of Ce is given in the attached paper. Full atomic absorption background for nearby elements Cs and Xe can be seen in the second attached paper. Some other useful references on this topic are given below: J. A. Solera, J. Garcia, M. G. Proietti, Phys. Rev. B 1995, 51, 2678–2686. A. Kodre, I. Arčon, M. Hribar, M. Štuhec, F. Villain, W. Drube, L. Troeger, Physica B 1995,208&209, 379–380. J. Padežnik Gomilšek, I. Kozjek Škofic, N. Bukovec, A. Kodre, Thin Solid Films 2004, 446, 117–123. E. Fonda, D. Andreatta, P. E. Colavita, G. Vlaic, J. Synchrotron Rad. 1999, 6, 34–42. also some our references for atomic absorption spectra of K edge exafs: A. Kodre, I. Arčon, J. Padežnik Gomilšek, R. Frahm Multielectron excitations in x-ray absorption spectra of Rb and Kr J. Phys. B: At. Mol. Opt. Phys. 35 (2002) 3497-3513 A. Kodre, I. Arčon, J. Padežnik Gomilšek, A. Mihelič Atomic absorption background in EXAFS spectra of Rb in inter-alkaline alloys Physica Scripta. Vol, T115, (2005) 218-220 A. Kodre, R. Prešeren, I. Arčon, J. Padeznik Gomilšek, M. Borowski, A study of transferability of atomic background on EXAFS spectra of simple gaseous compounds of As, J. Synch. Radiation 8 (2001) 282-284 R. Prešeren, A. Kodre, I. Arčon, M. Borowski, Atomic background and EXAFS of gaseous hydrides of Ge, As, Se, and Br, J. Synch. Radiation 8 (2001) 279-281 There are many other papers of different authors on the multielectron photoexcitations (see references in above papers). Additional information on multielectron photoexcitations in exafs spectra of L and K edges of different elements and some subtraction procedures can be found also on the dedicated web site of our group: http://www.p-ng.si/~arcon/xas/mpe/mpe5.htm best regards and congratulations for well supported program packages for exafs analysis. Iztok Arcon
On Tuesday 12 July 2005 11:18, QY ZML wrote:
I am analyzing EXAFS of some rare earth systems. It is known that there are ?multielectron transitions in these systems. So, I want to know how to subtract multielectron process contribution generally and if ATHENA has a feature to do this. ?Thank you very much.
Athena does not currently have a feature for doing this. Drat!
I would be willing to implement something empirical for doing this. I would like to see a discussion here on the mailing list of the merits of different approaches. Since I have never given this very much thought, I am not with any strong opinions for how it should (or should not) be done. But I can certainly consider implementing it.
B
-- Bruce Ravel ----------------------------------- bravel@anl.gov -or- ravel@phys.washington..edu
*** My cell phone number has changed. Please ask if you need the new number
Environmental Research Division, Building 203, Room E-165 Argonne National Laboratory phone and voice mail: (1) 630 252 5033 Argonne IL 60439, USA fax: (1) 630 252 9793
My homepage: http://feff.phys.washington.edu/~ravel EXAFS software: http://feff.phys.washington.edu/~ravel/software/exafs/
_______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit
participants (3)
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Bruce Ravel -
Iztok.Arcon＠p-ng.si -
QY ZML