Re: [Ifeffit] Feature near edge of Ni XANES spectrum
Hello Aditya, If I understand correctly, the nomenclature you are using is a little misleading. The sharp feature that you are referring to is a rising-edge feature and is not after the edge. The is a classic feature for square planar complexes and Ni does form a lot of those. The origin of this feature has been argued (in molecular systems) to be either: 1) Valence bond configuration interaction feature (VBCI), which is a formally forbidden 2 -electron transfer process. It gains intensity with covalent overlap of metal with ligands and has been shown (in the case of Cu(III) which is isoelectronic to Ni(II)) to increase with metal-ligand bond strength. 2) It has also been attributed to longer-range multiple scattering. It is important to realize that both effect increase in square planar systems and usually such a feature is the hallmark of a square planar molecule. Best, Riti On Tue, Feb 9, 2016 at 6:19 PM, Aditya Shivprasad wrote: > Dear list, > > I have obtained nickel XANES spectra (attached) from metallic Zircaloy-2 > nuclear fuel cladding (Zr, 1.5% Sn, 0.15% Fe, 0.1% Cr, 0.05% Ni). > > In the spectrum, I identify the edge as being approximately 8331-8332 eV > (based on maximum of first derivative), as it is for pure Ni. However, I > also identify a sharp feature at less than 1 eV past the edge. If anyone on > the list could help me to understand the origin of this feature, that would > be very helpful. > > Thanks > -- > Aditya Shivprasad > > aps...@psu.edu > Ph.D Candidate > Nuclear Engineering Department > Pennsylvania State University > > ___ > Ifeffit mailing list > Ifeffit@millenia.cars.aps.anl.gov > http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit > Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit > > ___ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit
[Ifeffit] Feature near edge of Ni XANES spectrum
Dear list, I have obtained nickel XANES spectra (attached) from metallic Zircaloy-2 nuclear fuel cladding (Zr, 1.5% Sn, 0.15% Fe, 0.1% Cr, 0.05% Ni). In the spectrum, I identify the edge as being approximately 8331-8332 eV (based on maximum of first derivative), as it is for pure Ni. However, I also identify a sharp feature at less than 1 eV past the edge. If anyone on the list could help me to understand the origin of this feature, that would be very helpful. Thanks -- Aditya Shivprasad aps...@psu.edu Ph.D Candidate Nuclear Engineering Department Pennsylvania State University Ni in Zircaloy-2.prj Description: Binary data ___ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit
Re: [Ifeffit] Ifeffit Digest, Vol 156, Issue 4
I have an SDD and find very little strength in the escape peak or the Si Ka peak. I have seen Si from the sample. I can't speak to how well Si XAS works because my beamline doesn't go down that far. mam On 2/9/2016 10:25 AM, Pierre Lecante wrote: Hi Pinit, here is what you can expect from a SDD: "At X-ray energies greater than silicon K absorption edge, which we have measured for crystalline silicon to be 1839 eV, the response function of the device shows two distinct peaks in addition to the primary one. One of them at energy /E/_/f/ = 1739 eV is due to the silicon fluorescent photons that have escaped far enough from the original site of interaction to be detected as a separate event. The other peak centered at energy /E/_/e/ = /E/_0 - /E/_/f/ , where /E/_0 is energy of the incident photon, is called an escape peak." So, indeed this shouldn't be a concern if you had a perfect rejection of harmonics on your beamline; if not, inelastic scattering of harmonic by the sample, even rejected by energy analysis, should likely induce internal fluorescence and escape peaks not observed in TM. Just an hypothesis, but easy to check: presence or not of harmonic in your scattering. Pierre Le 02/02/2016 23:41, ifeffit-requ...@millenia.cars.aps.anl.gov a écrit : Send Ifeffit mailing list submissions to ifeffit@millenia.cars.aps.anl.gov To subscribe or unsubscribe via the World Wide Web, visit http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit or, via email, send a message with subject or body 'help' to ifeffit-requ...@millenia.cars.aps.anl.gov You can reach the person managing the list at ifeffit-ow...@millenia.cars.aps.anl.gov When replying, please edit your Subject line so it is more specific than "Re: Contents of Ifeffit digest..." Today's Topics: 1. Re: Could you please give me some information? (Bruce Ravel) 2. Re: Athena with IOS "El Capitan" (Manuel Cossio Kohler) 3. Re: Athena with IOS "El Capitan" (Bruce Ravel) 4. Re: Athena with IOS "El Capitan" (Manuel Cossio Kohler) -- Message: 1 Date: Tue, 2 Feb 2016 15:30:45 -0500 From: Bruce Ravel To: pinit Cc: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] Could you please give me some information? Message-ID:<56b111f5.7050...@bnl.gov> Content-Type: text/plain; charset=windows-1252; format=flowed On 02/01/2016 11:58 PM, pinit wrote: Dear Bruce, I am Pinit from SLRI, Thailand. I have some questions concerning the Si-drift detector. Could you give me some suggestions if Si-detector can detect the corrected Si K-edge or not? This is because I have seen a significant EXAFS signal (higher in amplitude in FT) measured by Si-drift detector differs from Lytle detector or ionization chambers (TM mode). Hi Pinit, Nice to hear from you. I am CCing my answer to the Ifeffit Mailing List. Someone else may have more insight into your question than I do. You should CC the list in your response. I'd probably need to know more about the sample and the nature of the measurement you made to understand why you are seeing a different signal with the Si drift detector. Normally one would expect that he EXAFS would be /attenuated/ either due to self-absorption or due to the energy dependence of the I0 detector. That you are seeing a larger EXAFS signal with the Si-drift seems surprising. One thing that occurs to me is that the Compton and elastic peaks probably overlap the Si K alpha ROI quite a bit, even extending into the EXAFS region. I would have thought that, too, would serve to attenuate the EXAFS (but maybe I am thinking about that wrongly). Perhaps it would help to show us some of the data...? B -- Groupe MC2 CEMES-CNRS, 29 rue Jeanne Marvig, 31055 Toulouse Cedex 4, France Tel: +33 (0)5 62 25 78 51, Fax: +33 (0)5 62 25 79 99 Email:leca...@cemes.fr http://www.cemes.fr/MC2 Full list of publications: http://www.researcherid.com/rid/A-8745-2011 ___ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit ___ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit
Re: [Ifeffit] Could you please give me some information?
Hi Pinit, here is what you can expect from a SDD: "At X-ray energies greater than silicon K absorption edge, which we have measured for crystalline silicon to be 1839 eV, the response function of the device shows two distinct peaks in addition to the primary one. One of them at energy /E/_/f/ = 1739 eV is due to the silicon fluorescent photons that have escaped far enough from the original site of interaction to be detected as a separate event. The other peak centered at energy /E/_/e/ = /E/_0 - /E/_/f/ , where /E/_0 is energy of the incident photon, is called an escape peak." So, indeed this shouldn't be a concern if you had a perfect rejection of harmonics on your beamline; if not, inelastic scattering of harmonic by the sample, even rejected by energy analysis, should likely induce internal fluorescence and escape peaks not observed in TM. Just an hypothesis, but easy to check: presence or not of harmonic in your scattering. Pierre Le 02/02/2016 23:41, ifeffit-requ...@millenia.cars.aps.anl.gov a écrit : Send Ifeffit mailing list submissions to ifeffit@millenia.cars.aps.anl.gov To subscribe or unsubscribe via the World Wide Web, visit http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit or, via email, send a message with subject or body 'help' to ifeffit-requ...@millenia.cars.aps.anl.gov You can reach the person managing the list at ifeffit-ow...@millenia.cars.aps.anl.gov When replying, please edit your Subject line so it is more specific than "Re: Contents of Ifeffit digest..." Today's Topics: 1. Re: Could you please give me some information? (Bruce Ravel) 2. Re: Athena with IOS "El Capitan" (Manuel Cossio Kohler) 3. Re: Athena with IOS "El Capitan" (Bruce Ravel) 4. Re: Athena with IOS "El Capitan" (Manuel Cossio Kohler) -- Message: 1 Date: Tue, 2 Feb 2016 15:30:45 -0500 From: Bruce Ravel To: pinit Cc: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] Could you please give me some information? Message-ID: <56b111f5.7050...@bnl.gov> Content-Type: text/plain; charset=windows-1252; format=flowed On 02/01/2016 11:58 PM, pinit wrote: Dear Bruce, I am Pinit from SLRI, Thailand. I have some questions concerning the Si-drift detector. Could you give me some suggestions if Si-detector can detect the corrected Si K-edge or not? This is because I have seen a significant EXAFS signal (higher in amplitude in FT) measured by Si-drift detector differs from Lytle detector or ionization chambers (TM mode). Hi Pinit, Nice to hear from you. I am CCing my answer to the Ifeffit Mailing List. Someone else may have more insight into your question than I do. You should CC the list in your response. I'd probably need to know more about the sample and the nature of the measurement you made to understand why you are seeing a different signal with the Si drift detector. Normally one would expect that he EXAFS would be /attenuated/ either due to self-absorption or due to the energy dependence of the I0 detector. That you are seeing a larger EXAFS signal with the Si-drift seems surprising. One thing that occurs to me is that the Compton and elastic peaks probably overlap the Si K alpha ROI quite a bit, even extending into the EXAFS region. I would have thought that, too, would serve to attenuate the EXAFS (but maybe I am thinking about that wrongly). Perhaps it would help to show us some of the data...? B -- Groupe MC2 CEMES-CNRS, 29 rue Jeanne Marvig, 31055 Toulouse Cedex 4, France Tel: +33 (0)5 62 25 78 51, Fax: +33 (0)5 62 25 79 99 Email: leca...@cemes.fr http://www.cemes.fr/MC2 Full list of publications: http://www.researcherid.com/rid/A-8745-2011 ___ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit
Re: [Ifeffit] Ifeffit Digest, Vol 156, Issue 4
Hi Pinit, here is what you can expect from a SDD: "At X-ray energies greater than silicon K absorption edge, which we have measured for crystalline silicon to be 1839 eV, the response function of the device shows two distinct peaks in addition to the primary one. One of them at energy /E/_/f/ = 1739 eV is due to the silicon fluorescent photons that have escaped far enough from the original site of interaction to be detected as a separate event. The other peak centered at energy /E/_/e/ = /E/_0 - /E/_/f/ , where /E/_0 is energy of the incident photon, is called an escape peak." So, indeed this shouldn't be a concern if you had a perfect rejection of harmonics on your beamline; if not, inelastic scattering of harmonic by the sample, even rejected by energy analysis, should likely induce internal fluorescence and escape peaks not observed in TM. Just an hypothesis, but easy to check: presence or not of harmonic in your scattering. Pierre Le 02/02/2016 23:41, ifeffit-requ...@millenia.cars.aps.anl.gov a écrit : Send Ifeffit mailing list submissions to ifeffit@millenia.cars.aps.anl.gov To subscribe or unsubscribe via the World Wide Web, visit http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit or, via email, send a message with subject or body 'help' to ifeffit-requ...@millenia.cars.aps.anl.gov You can reach the person managing the list at ifeffit-ow...@millenia.cars.aps.anl.gov When replying, please edit your Subject line so it is more specific than "Re: Contents of Ifeffit digest..." Today's Topics: 1. Re: Could you please give me some information? (Bruce Ravel) 2. Re: Athena with IOS "El Capitan" (Manuel Cossio Kohler) 3. Re: Athena with IOS "El Capitan" (Bruce Ravel) 4. Re: Athena with IOS "El Capitan" (Manuel Cossio Kohler) -- Message: 1 Date: Tue, 2 Feb 2016 15:30:45 -0500 From: Bruce Ravel To: pinit Cc: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] Could you please give me some information? Message-ID: <56b111f5.7050...@bnl.gov> Content-Type: text/plain; charset=windows-1252; format=flowed On 02/01/2016 11:58 PM, pinit wrote: Dear Bruce, I am Pinit from SLRI, Thailand. I have some questions concerning the Si-drift detector. Could you give me some suggestions if Si-detector can detect the corrected Si K-edge or not? This is because I have seen a significant EXAFS signal (higher in amplitude in FT) measured by Si-drift detector differs from Lytle detector or ionization chambers (TM mode). Hi Pinit, Nice to hear from you. I am CCing my answer to the Ifeffit Mailing List. Someone else may have more insight into your question than I do. You should CC the list in your response. I'd probably need to know more about the sample and the nature of the measurement you made to understand why you are seeing a different signal with the Si drift detector. Normally one would expect that he EXAFS would be /attenuated/ either due to self-absorption or due to the energy dependence of the I0 detector. That you are seeing a larger EXAFS signal with the Si-drift seems surprising. One thing that occurs to me is that the Compton and elastic peaks probably overlap the Si K alpha ROI quite a bit, even extending into the EXAFS region. I would have thought that, too, would serve to attenuate the EXAFS (but maybe I am thinking about that wrongly). Perhaps it would help to show us some of the data...? B -- Groupe MC2 CEMES-CNRS, 29 rue Jeanne Marvig, 31055 Toulouse Cedex 4, France Tel: +33 (0)5 62 25 78 51, Fax: +33 (0)5 62 25 79 99 Email: leca...@cemes.fr http://www.cemes.fr/MC2 Full list of publications: http://www.researcherid.com/rid/A-8745-2011 ___ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit
