lifetime broadening of pre-edge peaks?
Is the core-hole lifetime broadening of pre-edge XANES peaks the same as at the main edge? I'm looking into issues of de-noising of XANES epsctra, so need to figure out how narrow real features can be. mam
Dear Matthew you can find examples of determination of life-time broadening, deconvolution of XANES specra, and discussion about limitations due to noise in several papers, for example: A. Filipponi, J. Phys. B 33, 2835 (2000) * A. Kodre, I. Arčon, J. Padeznik Gomilšek, R. Frahm*// J. Phys. B: At. Mol. Opt. Phys. 35 (2002) 3497-3513 *A. Kodre, J. Padežnik Gomilšek, A. Mihelič, I. Arcon*/ /Radiation Physics and Chemistry 75 (2006) 188-194 *J. Padeznik Gomilsek, I. Arcon, S. de Panfilis, A. Kodre,* / /Phys. Rev. A 79, (2009) 032514, regards Iztok Matthew Marcus wrote:
Is the core-hole lifetime broadening of pre-edge XANES peaks the same as at the main edge? I'm looking into issues of de-noising of XANES epsctra, so need to figure out how narrow real features can be. mam _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit
-- prof. dr. Iztok Arcon University of Nova Gorica Vipavska 13, POB 301 5001 Nova Gorica, Slovenia tel: +386 5 331 5227 fax: +386 5 331 5240 e-mail: iztok.arcon@ung.si http://www.ung.si/~arcon http://www.ung.si/~arcon/xas
Thanks. While none of these have to do with pre-edge peaks such as are found in transition-metal oxides, the assumption of constancy of core-hole broadening does seem to work. mam ----- Original Message ----- From: Iztok Arčon To: XAFS Analysis using Ifeffit Sent: Monday, October 10, 2011 12:32 AM Subject: Re: [Ifeffit] lifetime broadening of pre-edge peaks? Dear Matthew you can find examples of determination of life-time broadening, deconvolution of XANES specra, and discussion about limitations due to noise in several papers, for example: A. Filipponi, J. Phys. B 33, 2835 (2000) A. Kodre, I. Arčon, J. Padeznik Gomilšek, R. Frahm J. Phys. B: At. Mol. Opt. Phys. 35 (2002) 3497-3513 A. Kodre, J. Padežnik Gomilšek, A. Mihelič, I. Arcon Radiation Physics and Chemistry 75 (2006) 188-194 J. Padeznik Gomilsek, I. Arcon, S. de Panfilis, A. Kodre, Phys. Rev. A 79, (2009) 032514, regards Iztok Matthew Marcus wrote: Is the core-hole lifetime broadening of pre-edge XANES peaks the same as at the main edge? I'm looking into issues of de-noising of XANES epsctra, so need to figure out how narrow real features can be. mam _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit -- prof. dr. Iztok Arcon University of Nova Gorica Vipavska 13, POB 301 5001 Nova Gorica, Slovenia tel: +386 5 331 5227 fax: +386 5 331 5240 e-mail: iztok.arcon@ung.si http://www.ung.si/~arcon http://www.ung.si/~arcon/xas ------------------------------------------------------------------------------ _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit
I think experimental answer could be the simplest one. Perhaps there is anyone on the list who measured low concentrations of low Z absorber in the high Z host at both edges? For example, Cu in Ag (if does dissolve in Ag if made by rapid quenching) at Cu K-edge, and Ag K-edge (or just bulk Ag since the data will be the same). These should be solid solutions, of course. Then, despite the difference in phase shift, the EXAFS oscillations should be comparable in magnitude if the broadening is not significant, and it should be more intense for the Cu K-edge if the broadening at Ag K edge is significant. Another option: to hear from people doing HERFD. That is normally done on XANES, for the reason, I assume, that they do not see any advantage in EXAFS region, where broadening does not change compared to total fluorescence. I think the explanation that EXAFS should not be too sensitive to the life time broadening is that EXAFS originates from the final state interference, while the XANES - from both the final state interference and DOS. But may be experiments are showing the opposite, and that will prove me wrong. Anatoly ________________________________ From: ifeffit-bounces@millenia.cars.aps.anl.gov [ifeffit-bounces@millenia.cars.aps.anl.gov] on behalf of Matthew Marcus [mamarcus@lbl.gov] Sent: Monday, October 10, 2011 2:23 PM To: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] lifetime broadening of pre-edge peaks? Thanks. While none of these have to do with pre-edge peaks such as are found in transition-metal oxides, the assumption of constancy of core-hole broadening does seem to work. mam ----- Original Message ----- From: Iztok Arčonmailto:iztok.arcon@ung.si To: XAFS Analysis using Ifeffitmailto:ifeffit@millenia.cars.aps.anl.gov Sent: Monday, October 10, 2011 12:32 AM Subject: Re: [Ifeffit] lifetime broadening of pre-edge peaks? Dear Matthew you can find examples of determination of life-time broadening, deconvolution of XANES specra, and discussion about limitations due to noise in several papers, for example: A. Filipponi, J. Phys. B 33, 2835 (2000) A. Kodre, I. Arčon, J. Padeznik Gomilšek, R. Frahm J. Phys. B: At. Mol. Opt. Phys. 35 (2002) 3497-3513 A. Kodre, J. Padežnik Gomilšek, A. Mihelič, I. Arcon Radiation Physics and Chemistry 75 (2006) 188-194 J. Padeznik Gomilsek, I. Arcon, S. de Panfilis, A. Kodre, Phys. Rev. A 79, (2009) 032514, regards Iztok Matthew Marcus wrote: Is the core-hole lifetime broadening of pre-edge XANES peaks the same as at the main edge? I'm looking into issues of de-noising of XANES epsctra, so need to figure out how narrow real features can be. mam _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.govmailto:Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit -- prof. dr. Iztok Arcon University of Nova Gorica Vipavska 13, POB 301 5001 Nova Gorica, Slovenia tel: +386 5 331 5227 fax: +386 5 331 5240 e-mail: iztok.arcon@ung.simailto:iztok.arcon@ung.si http://www.ung.si/~arcon http://www.ung.si/~arcon/xas ________________________________ _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit
Hi Matthew,
On Sat, Oct 8, 2011 at 4:36 PM, Matthew Marcus
Is the core-hole lifetime broadening of pre-edge XANES peaks the same as at the main edge? I'm looking into issues of de-noising of XANES epsctra, so need to figure out how narrow real features can be. mam
I'm sure others are more knowledgeable about this, but I think the answer is the classic "yes, but...". The "yes" part would be: Yes, the core-hole energy width doesn't depend on the final state. The "but" part would be: But that assumes (I think) that the final state has lost all connection to the core level, except the principle quantum number (that is, it has to be p-like for an s hole). That assumption isn't exactly true for bound atomic/molecular states that give the pre-edge peaks, as there is some spin information preserved. I think regular XANES measurements of the pre-edge peaks do include the full core-hole lifetime. But, has been demonstrated many times, with high-energy resolution of the emission (RIXS), one can beat the core-hole lifetime, as the energy-selected emission can come from only a limited portion of the full core-hole energy width. Hopefully, someone will correct any errors in this... --Matt
participants (4)
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Anatoly I Frenkel
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Iztok Arčon
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Matt Newville
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Matthew Marcus