- Ifeffit - millenia.cars.aps.anl.gov

Question about Air sensitive sample holder
by Helen Chen 26 Mar '25

26 Mar '25

Hello, Our group (Jerry Seidler) just started a project involving doing VTC and HERFD on Yb doped CrX3 material. They are thin small crystal sheets and are very air sensitive. We have tried encapsulated them between a layer of laptop tape and film, but after 12hr we see degradation due to air leaks. I am looking for some advice on air sensitive sample holder. What are some typical methods you use to deal with air sensitivity, especially for samples in thin sheets geometry? Thank you

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XAFS19 Abstract Submissions open
by Carlo Segre 17 Mar '25

17 Mar '25

Hello All, The abstract submission page on the XAFS19 Conference web site will be open later this afternoon. You will be able to request a poster or oral presentation. The Program Committee will make the final decisions on which format your work will be presented. For those of you who need an invitation letter for a Visa, please email xafsconference2025(a)gmail.com to request one with your abstract number. For the XAFS19<https://urldefense.us/v3/__https://www.icdd.com/xafs19/__;!!G_uCfscf7eWS!Zj… > organizing committee, Carlo -- Carlo Segre, Duchossois Professor of Physics Illinois Institute of Technology

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PostDoc position as Beamline Scientist at KIT Light Source
by Zimina, Anna (IKFT) 14 Mar '25

14 Mar '25

Dear all, Postdoc position for the challenging job at KIT Light Source synchtrotron as beamline scientist at the X-ray absorption spectroscopy beamline is open in our group at IKFT/KIT: https://www.pse.kit.edu/english/karriere/joboffer.php?id=164965 Curious? Find out more here: https://www.ikft.kit.edu/english/234.php Please forward the advertisement further. Thank you in advance, Anna Zimina ____________________________________________________________________________ __________ Karlsruhe Institute of Technology (KIT) Institute of Catalysis Research and Technology (IKFT) Dr. Anna Zimina Catalysis at KIT Light Source group Hermann-von-Helmholtz-Platz 1 Building 345 Office 304 76344 Eggenstein-Leopoldshafen Phone: +49 721 608 28673 Fax: +49 721 608 26789 E-Mail <mailto:anna.zimina@kit.edu> anna.zimina(a)kit.edu

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XANES reference Spectra of V2O5 and VO2
by Dooshaye Moonshiram 14 Mar '25

14 Mar '25

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Athena - LCF component export error
by miranda.vu＠lightsource.ca 10 Mar '25

10 Mar '25

Hi, I am having an issue with the export of LCF data in Athena version 0.9.26. When I export the .lcf of files, it will re-order the components without properly re-ordering the associated data columns. The data and components will plot correctly in Athena before exporting. Is this something that can be fixed? Or if not would it be possible for me to get version 0.9.24 if you still have a copy of it? Please let me know if there is any additional information that I can provide. Thanks, Miranda

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International XAFS Conference 19 - Chicago July 14-18, 2025
by Carlo Segre 05 Mar '25

05 Mar '25

Hello IFEFFIT Mailing List, I am pleased to let you know that the website and registration pages for the XAFS19 conference to be held on the Illinois Tech Main Campus in Chicago, Illinois, July 14-18 is now available. The links to the registration for participants and exhibitors are both live and we are able to take registration. Members of the International XAFS Society can take advantage of the discount on the full participant registration fee with a promotion code that will be available shortly from the Society. The Abstract submission will open early next week and I will send an additional announcement out at that time. Please bear with us as the web site is still a work in progress. Housing information as well as more information regarding invited speakers is forthcoming. The link to the main conference web site is https://urldefense.us/v3/__https://www.icdd.com/xafs19/__;!!G_uCfscf7eWS!cy… . Please feel free to disseminate this announcement. For any questions, please email the conference at <xafsconference2025(a)gmail.com>. This email will be used for individual correspondence. If you have corrections about the web site, please feel free to email me at <segre(a)iit.edu>. Carlo Segre for the XAFS19 Local Organizing Committee -- Carlo Segre, Duchossois Professor of Physics Illinois Institute of Technology

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Water-free binder advice
by Paul Aronstein 01 Mar '25

01 Mar '25

Hello, I'm looking for some advice on binder alternatives for preparing either pellets or packed powder samples in a dry glovebox. Please also note if the binder requires preparation (i.e. desiccated prior to use, etc) or if there are other considerations. Thank you, -Paul

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Question about Ti edge
by Benito Melas 01 Mar '25

01 Mar '25

Hi all, I was following this article about Li2TiS3 https://urldefense.us/v3/__https://pubs.acs.org/doi/full/10.1021/acs.inorgc… and found this Ti edge XANES figure [image: image.png] The authors claim The peak position for LTS-213 is approximately 4970 eV, which agrees well > with that for rutile TiO2 with a valence of titanium species in the 4+ > oxidation state. Should we use the pre-edge to determine the oxidation state? Is it reliable, or should we use E₀ and compare it with references of well-known oxidation states? > In addition, TiS2, in which titanium is also in the 4+ oxidation state, > shows pre-edge peaks at 4968–4971 eV. (21) Considering the titanium > oxidation state in the raw materials, the stability of the titanium > species, and the XANES results, the oxidation state of the titanium species > in LTS-213 is likely to be 4+. The second conclusion is even more unclear. Would you help me see if I am missing something in my understanding of oxidation states using XANES? Best, B.

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Re: Question about Ti edge
by Benito Melas 28 Feb '25

28 Feb '25

Hi Matt, Thank you for the explanation. In this case, comparing oxides provides only a rough approximation of the oxidation states. Using both oxides and sulfides would incorporate the contribution of covalency and lead to inaccuracies. What about utilizing the pre-edge mixing oxides and sulfides? I have a concept that is more related to the symmetry of the site, although this understanding also originates from oxides. Best regards, On Fri, Feb 28, 2025 at 11:54 PM matt.newville(a)gmail.com < matt.newville(a)gmail.com> wrote: > Hi Benito, > > > > The energy of the sharp rise (ie, the energy of the empty metal 4p states) > is a simple measure of the “charge state” or “oxidation state” of a > metal. To be clear, for a particular ligand type (say, oxygen), the > energy of 4p states, and so also the energy of the main rise in mu(E), will > change systematically with energy. But if you change the ligand, and the > covalency/ionicity of the bond, that will also move the energy of the > metal’s 4p states. Metal sulfides are much more covalent than metal > sulfides, and many are semi-metallic. If I understand correctly, titanium > disulfide is used because it is electrically conductive. > > > > OTOH, titanium dioxide will have a band gap of a couple of eV. That “band > gap” is strongly correlated with the edge shift. > > > > Again, the energy of the “main edge” is just not a simple measure of > “oxidation state”, especially if the ligand is not oxygen. > > Using the term “oxidation state” for a sulfide is not going to give you > much insight. > > > > --Matt > > > > > > *From: *Benito Melas <metal.cnea(a)gmail.com> > *Date: *Friday, February 28, 2025 at 7:58 AM > *To: *matt.newville(a)gmail.com <matt.newville(a)gmail.com> > *Subject: *Re: [Ifeffit] Question about Ti edge > > Hi Matt, > As you mentioned, "for the transition metals, there will usually be a > sharp rise in mu(E) at the energy." > In the case of LTS, however, this sharp rise occurs at lower energies than > in TiO2, which raises concerns regarding the claim that both compounds > exhibit the same oxidation state. > Thank you for your continued dedication to enlightening our community. > Best regards, > > > > > > > > On Fri, Feb 28, 2025 at 3:46 AM matt.newville(a)gmail.com < > matt.newville(a)gmail.com> wrote: > > Hi Benito, > > > > > The authors claim > > >> The peak position for LTS-213 is approximately 4970 eV, which agrees > well with that for rutile TiO2 with a valence of titanium species in the 4+ > oxidation state. > > > > > Should we use the pre-edge to determine the oxidation state? Is it > reliable, or should we use E₀ and compare it with references of well-known > oxidation states? > > > > Many people use pre-edge peaks of transition metals for reliable analysis > of metal oxidation states. > > > > E0 is sort of poorly defined term. For the transition metals, there will > usually be a sharp rise in mu(E) at the energy of the metal’s own 4p > electrons – the “main edge”, though this can sometimes be tricky to > identify precisely, and sometimes has structure (as TiO2 does – slightly > different for its different forms). > > > > >> In addition, TiS2, in which titanium is also in the 4+ oxidation state, > shows pre-edge peaks at 4968–4971 eV. (21) Considering the titanium > oxidation state > > >> in the raw materials, the stability of the titanium species, and the > XANES results, the oxidation state of the titanium species in LTS-213 is > likely to be 4+. > > > The second conclusion is even more unclear. > > What confuses me there is “TiS2 is in the 4+ *oxidation* state”. > Titanium disulfide is not oxidized at all - it is bound to sulfur. Its > charge state could be 4+, and many chemists use “oxidation” to mean the > transfer of charge to and from a metal, whether this is done by oxygen or > not. For XANES, the ligand species matters. K-edge XANES shows the > energies of the unfilled p states at the center of the Ti atom, which will > be very different for Ti-S (more covalent) and Ti-O (more ionic) bonds. > > --Matt > > > > > > *From: *Benito Melas via Ifeffit <ifeffit(a)millenia.cars.aps.anl.gov> > *Date: *Thursday, February 27, 2025 at 7:28 AM > *To: *ifeffit(a)millenia.cars.aps.anl.gov <ifeffit(a)millenia.cars.aps.anl.gov > > > *Cc: *Benito Melas <metal.cnea(a)gmail.com> > *Subject: *[Ifeffit] Question about Ti edge > > Hi all, I was following this article about Li2TiS3 https: //pubs. acs. > org/doi/full/10. 1021/acs. inorgchem. 4c03864 and found this Ti edge > XANES figure The authors claim The peak position for LTS-213 is > approximately 4970 eV, which agrees well with > > ZjQcmQRYFpfptBannerStart > > *This Message Is From an External Sender * > > This message came from outside your organization. > > ZjQcmQRYFpfptBannerEnd > > Hi all, > > I was following this article about Li2TiS3 > > > https://urldefense.us/v3/__https://pubs.acs.org/doi/full/10.1021/acs.inorgc… > <https://urldefense.us/v3/__https:/pubs.acs.org/doi/full/10.1021/acs.inorgch…> > > > and found this Ti edge XANES figure > > > The authors claim > > > > The peak position for LTS-213 is approximately 4970 eV, which agrees well > with that for rutile TiO2 with a valence of titanium species in the 4+ > oxidation state. > > > > Should we use the pre-edge to determine the oxidation state? Is it > reliable, or should we use E₀ and compare it with references of well-known > oxidation states? > > > > In addition, TiS2, in which titanium is also in the 4+ oxidation state, > shows pre-edge peaks at 4968–4971 eV. (21) Considering the titanium > oxidation state in the raw materials, the stability of the titanium > species, and the XANES results, the oxidation state of the titanium species > in LTS-213 is likely to be 4+. > > > > The second conclusion is even more unclear. > > Would you help me see if I am missing something in my understanding of > oxidation states using XANES? > > > > Best, B. > > > >

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Diatomic distance on each EXAFS of both elements
by "Qiang Chang (常强)" 27 Feb '25

27 Feb '25

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