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Question on (Combo-) LCF plot output
by t.zahoransky＠mineralogie.uni-hannover.de 30 Mar '20

30 Mar '20

Dear Mailing list, I am a relatively new user in terms of XAS data handling and I encountered a strange problem during LCF in Athena. I am working on LCF-combo fittings for Mn minerals as described in Manceau et al. 2012*. Fitting f.ex. a cryptomelane sample of myself with the open source monovalent manganese mineral standards of Manceau et al. 2012 in a fit range of -20 to +30 k, gives the following result shown below (I´ll attach the Athena project): " LCF fit of Cryptomelane_T_20K_ecd as flattened mu(E) from 6536.79 to 6586.79 Fit included 100 data points and 6 variables, and approximately 41.333 measurements Weights sum to 1: no Weights forced between 0 and 1: no Overall e0 shift used: yes Noise added to data: 0 R-factor = 0.0003537 Chi-square = 0.00815 Reduced chi-square = 0.0000858 . standard weight e0 ======================================================== . Manganosite.dat 0.042 (0.006) 1.631 (0.044) . Groutite.dat 0.030 (0.029) 1.631 (0.044) . Ca2Mn3O8.dat 0.288 (0.026) 1.631 (0.044) . Ramsdellite.dat 0.584 (0.022) 1.631 (0.044) . Mn2O3.dat 0.044 (0.025) 1.631 (0.044) . sum ........... 0.988 " Note that the box “all standards share an E0” is checked before clicking on “Fit this group”. Optically, the fit itself “looks” good compared to the data, yet, it is somewhat shifted on the x-axis compared to the data. I was wondering why, as this was not the first sample where this was the case. When I now uncheck the “All standards share an E0” box, leave everything else just the way it is and just click “Fit this group” again, the fit suddenly is shifted perfectly on my data. The strange thing is: Nothing else in the output-results changes – weights, R-factor, chi-square etc. just stay the same. Only slight changes in the numbers in brackets after the reported weights. The "new" result is: " LCF fit of Cryptomelane_Mikon_T_20K_ecd_reb-a-m as flattened mu(E) from 6536.79 to 6586.79 Fit included 100 data points and 5 variables, and approximately 41.333 measurements Weights sum to 1: no Weights forced between 0 and 1: no Overall e0 shift used: no Noise added to data: 0 R-factor = 0.0003537 Chi-square = 0.00815 Reduced chi-square = 0.0000849 . standard weight e0 ======================================================== . Mn2O3.dat 0.044 (0.024) 1.631 (0.000) . Manganosite.dat 0.042 (0.006) 1.631 (0.000) . Ca2Mn3O8.dat 0.288 (0.024) 1.631 (0.000) . Ramsdellite.dat 0.584 (0.019) 1.631 (0.000) . Groutite.dat 0.030 (0.026) 1.631 (0.000) . sum ........... 0.988 " Can anybody tell me, what is actually happening? I exported both data to excel to replot the fits to exclude a simple plot-bug, but the data behind show that this is real. So, I am changing the data behind the plot, but actually not the output data … what is going on here? You find the project attached – I hope someone can tell me, how to cope with that! Thank you very much, Teresa *Manceau, A., Marcus, M. A., & Grangeon, S. (2012). Determination of Mn valence states in mixed-valent manganates by XANES spectroscopy. American Mineralogist, 97(5-6), 816-827. -- Teresa Zahoransky Soil Mineralogy Gottfried Wilhelm Leibniz Universität Hannover Institute of Mineralogy Callinstr. 3, Room 325 D-30167 Hannover, Germany Phone: +49 (0)511 762-8058 Email: t.zahoransky(a)mineralogie.uni-hannover.de

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Yoshio Waseda database
by Pierre LECANTE 12 Mar '20

12 Mar '20

Dear XAS users, I have a problem and maybe you can help or point me to a suitable source: from time to time I used the database from Professor Yoshio Waseda, especially the structural database on molten metals measured by X-ray scattering, just like Farell-Lytle Database but for PDF studies; address was: http://ies.tagen.tohopku.ac.ip/~waseda/scm/AXS/index.html however it seems to be no more accessible and the change is relatively recent; any information on the problem or actually on a way to access such structural information should be greatly appreciated! sincerely, Pierre -- Groupe SINanO 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: lecante(a)cemes.fr http://www.cemes.fr/SINanO-Surfaces-Interfaces-et-Nano-Objets Full list of publications: http://www.researcherid.com/rid/A-8745-2011 http://orcid.org/0000-0001-6337-6855

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Unable to access content on millenia.cars.aps.anl.gov website
by Jullieta Lum 09 Mar '20

09 Mar '20

Good Day, I need assistance with accessing content on the iffefit website. I am subscribed to the mail list and receive the digest. However, I am unable to open any of the past questions and answers which I could do before. Hoping you can assist. Kind Regards, Jullieta

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PhD position in XAS for catalysis at ESRF
by Kirill LOMACHENKO 05 Mar '20

05 Mar '20

Dear all, it is my pleasure to inform you that we have opened a PhD position at BM23 and ID24 XAS beamlines of the ESRF (Grenoble, France). The focus of the PhD project is on the operando XAS and XES studies of novel industrial deNOx catalysts. The position is funded by a European program InnovaXN. The student will be hosted in ESRF, but will also have internships at Umicore Denmark (industrial partner) and University of Turin (academic partner). Full description of the project and the application form are here: https://esrf.gestmax.eu/1396/1/phd-position-operando-xas-dor-denox-catalysi… I would be grateful if you could forward this info to your colleagues and students who might be interested. Best regards, Kirill Lomachenko -- Dr. Kirill A. Lomachenko Scientist at BM23/ID24 beamlines European Synchrotron Radiation Facility 71 avenue des Martyrs CS 40220 38043 Grenoble Cedex 9, France Tel: +33 438 88 19 14 www.esrf.eu

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APS/IIT XAFS Summer School Announcement
by Carlo Segre 20 Feb '20

20 Feb '20

The 2020 APS/IIT Summer XAFS School will be held from July 12-17, 2020 in Chicago. Please see attached document for details and contact Grant Bunker <bunker(a)iit.edu> by email for more information with the subject line "2020 XAFS School". -- Carlo U. Segre -- Duchossois Leadership Professor of Physics Director, Center for Synchrotron Radiation Research and Instrumentation Illinois Institute of Technology Voice: 312.567.3498 Fax: 312.567.3494 segre(a)iit.edu http://phys.iit.edu/~segre segre(a)debian.org

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XAFS detection limit
by Christian Wittee Lopes 09 Feb '20

09 Feb '20

Dear all, Recently I was questioned about the EXAFS detection limit when describing different metal species in a bimetallic sample. By checking Pd and Cu K-edges, for example, I found Pd metal nanoparticles and CuO clusters, respectively. But additional techniques tell me I can have copper atoms in intimate contact with the Pd nanoparticles. What would be the minimum amount of these "single atoms" needed to be detected by EXAFS? is there a detection limit or it depends on several parameters? Thanks!!! -- *Christian Wittee Lopes* *Postdoctoral Researcher* Institute of Physics, Universidade Federal do Rio Grande do Sul (UFRGS) Phone: +55 54 992430264

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Re: [Ifeffit] Ifeffit Digest, Vol 204, Issue 1
by Christopher Chantler 07 Feb '20

07 Feb '20

Dear Christian and all I think we do not know yet, as the limits are getting better with improved techniques and error analysis, but it is a really good question. One can discuss limits from transmission versus fluorescence, in mM, in ppm; and separately perhaps in mass or mL or microL; or in e.g. atoms or molecules. I think every beamline has some guidelines, for their implementation. So yes it depends a lot on atomic number, density, need for a particular k range (e.g. XANES, normal XAFS, XERT etc.), beamline flux, and experimental method. Some of these estimates will be in the forthcoming International Tables for Crystallography, and earlier estimates are in earlier treatises. Best wishes, Chris -------------------------------------------------------------------------------------- Christopher Chantler, Professor, FAIP, Fellow American Physical Society Editor-in-Chief, Radiation Physics and Chemistry Chair, International IUCr Commission on XAFS; CIT, CCN IPP, International Radiation Physics Society School of Physics, University of Melbourne Parkville Victoria 3010 Australia +61-3-83445437 FAX +61-3-93474783 chantler(a)unimelb.edu.au<https://owa.unimelb.edu.au/owa/redir.aspx?C=c7BoS0kVVkC1_S95-9x9l5cBu6YTjdA…> chantler(a)me.com<https://owa.unimelb.edu.au/owa/redir.aspx?C=c7BoS0kVVkC1_S95-9x9l5cBu6YTjdA…> http://optics.ph.unimelb.edu.au/~chantler/xrayopt/xrayopt.html<https://owa.unimelb.edu.au/owa/redir.aspx?C=c7BoS0kVVkC1_S95-9x9l5cBu6YTjdA…> http://optics.ph.unimelb.edu.au/~chantler/home.html<https://owa.unimelb.edu.au/owa/redir.aspx?C=c7BoS0kVVkC1_S95-9x9l5cBu6YTjdA…> ________________________________ From: Ifeffit <ifeffit-bounces(a)millenia.cars.aps.anl.gov> on behalf of ifeffit-request(a)millenia.cars.aps.anl.gov <ifeffit-request(a)millenia.cars.aps.anl.gov> Sent: Saturday, 8 February 2020 5:00 AM To: ifeffit(a)millenia.cars.aps.anl.gov <ifeffit(a)millenia.cars.aps.anl.gov> Subject: Ifeffit Digest, Vol 204, Issue 1 Send Ifeffit mailing list submissions to ifeffit(a)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-request(a)millenia.cars.aps.anl.gov You can reach the person managing the list at ifeffit-owner(a)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. XAFS detection limit (Christian Wittee Lopes) ---------------------------------------------------------------------- Message: 1 Date: Thu, 6 Feb 2020 23:39:13 -0300 From: Christian Wittee Lopes <chriswittee(a)gmail.com> To: Ifeffit(a)millenia.cars.aps.anl.gov Subject: [Ifeffit] XAFS detection limit Message-ID: <CAJHLRaEz1SJ8dsA+WySAq4Uc2JR=cHApDQ+yZ+yHguqELU+tOw(a)mail.gmail.com> Content-Type: text/plain; charset="utf-8" Dear all, Recently I was questioned about the EXAFS detection limit when describing different metal species in a bimetallic sample. By checking Pd and Cu K-edges, for example, I found Pd metal nanoparticles and CuO clusters, respectively. But additional techniques tell me I can have copper atoms in intimate contact with the Pd nanoparticles. What would be the minimum amount of these "single atoms" needed to be detected by EXAFS? is there a detection limit or it depends on several parameters? Thanks!!! -- *Christian Wittee Lopes* *Postdoctoral Researcher* Institute of Physics, Universidade Federal do Rio Grande do Sul (UFRGS) Phone: +55 54 992430264

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XAFS.ORG WEBSITE??
by Bare, Simon R 30 Jan '20

30 Jan '20

Talking of websites does anyone know what happened to the International XAFS website? I can't access it. And what is going on with this organization? Thanks. Simon

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what happened to the website?
by Matthew Marcus 29 Jan '20

29 Jan '20

The http://millenia.cars.aps.anl.gov/ website seems to have gone off-line, which means that WebAtoms doesn't work anymore. Is there a replacement? Of course, I can use the stand-alone Atoms in Demeter. -- Sincerely, Matthew Marcus

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color of fonts in demeter
by Ricardo Faccio 29 Jan '20

29 Jan '20

Dear all After installing Demeter in MacOS I am having some problems related to the color of fonts and background. Since they look identical is diffcult to see and read. How could be possible to change the color of fonts? I am attaching an example. Best regards Ricardo -- ------------------------------------------------------------------------- Dr. Ricardo Faccio Prof. Agregado de Física (Assoc. Prof.) Mail: Área Física, DETEMA, Facultad de Química, Universidad de la República Av. Gral. Flores 2124, C.C. 1157 C.P. 11800, Montevideo, Uruguay. E-mail: rfaccio(a)fq.edu.uy Phone: (+598) 2924 9859 (+598) 2929 0648 Fax: (+598) 2924 1906 Web: http://cryssmat.fq.edu.uy/ricardo/ricardo.htm

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