BEGIN:VCALENDAR VERSION:2.0 PRODID:-//IXAS: The International X-ray Absorption Society - ECPv6.15.15//NONSGML v1.0//EN CALSCALE:GREGORIAN METHOD:PUBLISH X-WR-CALNAME:IXAS: The International X-ray Absorption Society X-ORIGINAL-URL:https://xrayabsorption.org X-WR-CALDESC:Events for IXAS: The International X-ray Absorption Society REFRESH-INTERVAL;VALUE=DURATION:PT1H X-Robots-Tag:noindex X-PUBLISHED-TTL:PT1H BEGIN:VTIMEZONE TZID:America/Los_Angeles BEGIN:DAYLIGHT TZOFFSETFROM:-0800 TZOFFSETTO:-0700 TZNAME:PDT DTSTART:20190310T100000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:-0700 TZOFFSETTO:-0800 TZNAME:PST DTSTART:20191103T090000 END:STANDARD BEGIN:DAYLIGHT TZOFFSETFROM:-0800 TZOFFSETTO:-0700 TZNAME:PDT DTSTART:20200308T100000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:-0700 TZOFFSETTO:-0800 TZNAME:PST DTSTART:20201101T090000 END:STANDARD BEGIN:DAYLIGHT TZOFFSETFROM:-0800 TZOFFSETTO:-0700 TZNAME:PDT DTSTART:20210314T100000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:-0700 TZOFFSETTO:-0800 TZNAME:PST DTSTART:20211107T090000 END:STANDARD END:VTIMEZONE BEGIN:VEVENT DTSTART;VALUE=DATE:20200604 DTEND;VALUE=DATE:20200605 DTSTAMP:20260416T074906 CREATED:20200512T160713Z LAST-MODIFIED:20200606T233732Z UID:367-1591228800-1591315199@xrayabsorption.org SUMMARY:Maryjo Brounce: The oxidation state of sulfur in Apollo-era lunar rocks and curation best practices for future sample return missions DESCRIPTION:Lunar apatites contain hundreds to thousands of parts per million of sulfur. This is puzzling because lunar basalts are thought to form in low oxygen fugacity (fO2) conditions where sulfur can only exist in its reduced form (S2–)\, a substitution not previously observed in natural apatite. We present measurements of the oxidation state of S in lunar apatites and associated mesostasis glass that show that lunar apatites and glass contain dominantly S2–\, whereas natural apatites from Earth are only known to contain S6+. It is likely that many terrestrial and martian igneous rocks contain apatites with mixed sulfur oxidation states. The S6+/S2– ratios of such apatites could be used to quantify the fO2 values at which they crystallized\, given information on the portioning of S6+ and S2– between apatite and melt and on the S6+/S2– ratios of melts as functions of fO2 and melt composition. Such a well-calibrated oxybarometer based on this the oxidation state of S in apatite would have wide application. \nReferences: \n\nBrounce\, M.\, Boyce\, J.\, McCubbin\, F.M.\, Humphreys\, J*.\, Reppart\, J.\, Stolper\, E.\, and Eiler\, J. (2019) The oxidation state of sulfur in lunar apatite. American Mineralogist\, 104\, 307-312. doi: https://doi.org/10.2138/am-2019-680\n\n  URL:https://xrayabsorption.org/events/journalclub-maryjo-brounce/ CATEGORIES:XAFS Journal Club END:VEVENT BEGIN:VEVENT DTSTART;VALUE=DATE:20200601 DTEND;VALUE=DATE:20200602 DTSTAMP:20260416T074906 CREATED:20200512T153844Z LAST-MODIFIED:20200604T042831Z UID:365-1590969600-1591055999@xrayabsorption.org SUMMARY:Anne Marie March: Capturing photochemical reaction intermediates with time-resolved synchrotron x-ray spectroscopy DESCRIPTION:The pump-probe technique allows for measurement of timescales that are shorter than a detector’s response time. Using a MHz-repetition-rate laser to pump a sample\, the full x-ray flux of synchrotrons such as the Advanced Photon Source (APS) can be used to probe the ensuing photoinduced reaction(s). The obtained time-resolved XAS and XES spectra can be used to capture the electronic and geometric structure of short lived intermediate species. In this presentation\, I will give a brief introduction to the pump-probe measurement technique as implemented at Sector 7 of the APS and present recent studies of the photoinduced aquation reaction of [FeII(CN)6]4-\, where we were able to detect an intermediate species with a lifetime 4x shorter than the x-ray probe pulse duration. \nReferences: \n\nhttps://doi.org/10.1063/1.5117318\nhttps://doi.org/10.1107/S1600577519012268\n\n  URL:https://xrayabsorption.org/events/journlclub-anne-marie-march/ CATEGORIES:XAFS Journal Club END:VEVENT BEGIN:VEVENT DTSTART;VALUE=DATE:20200528 DTEND;VALUE=DATE:20200529 DTSTAMP:20260416T074906 CREATED:20200512T030817Z LAST-MODIFIED:20200604T042648Z UID:310-1590624000-1590710399@xrayabsorption.org SUMMARY:Megan Holycross: Probing the deep Earth oxygen cycle with XANES DESCRIPTION:The oxidation state of the solid Earth influences\, to a first order\, the structure of the planet and the chemistry of rocks\, ores and volcanic gases; mass transfer of oxygen between terrestrial reservoirs enables a habitable world. Fe K-edge XANES spectroscopy shows magmas erupted from continental crust\, formed at subduction zones\, are more oxidized than magmas erupted from oceanic crust\, formed at mid-ocean ridges (e.g.\, Kelley and Cottrell 2009; Science). However\, there is long-standing debate over the timing and mechanism of the processes that produce oxidized continental crust. The high-pressure mineral phase garnet is a key reservoir of iron in the crust and garnet Fe3+/ƩFe ratios record the transfer of oxygen throughout the subduction process. Here\, I’ll use garnet Fe-XANES to quantify the oxidation state of two suites of subduction-related rocks to examine changes in the deep Earth oxygen cycle over space (scale of ~100 km) and time (scale of ~2.5 billion years). \nReferences: \n\n\n\nK. A.  Kelley and E. Cottrell\, Water and the Oxidation State of Subduction Zone Magmas Science  325\, pp 605  (2009)   https://doi.org/10.1126/science.1174156 \n\n\nM. D. Dyar\, et al\,  Accurate determination of ferric iron in garnets by bulk Mössbauer spectroscopy and synchrotron micro-XAS American Mineralogist 97 pp 1726–1740 (2012) https://doi.org/10.2138/am.2012.4107\n\n  \n  \n  URL:https://xrayabsorption.org/events/journalclub-megan-holycross/ CATEGORIES:XAFS Journal Club END:VEVENT BEGIN:VEVENT DTSTART;VALUE=DATE:20200525 DTEND;VALUE=DATE:20200526 DTSTAMP:20260416T074906 CREATED:20200512T031248Z LAST-MODIFIED:20200526T032812Z UID:312-1590364800-1590451199@xrayabsorption.org SUMMARY:Joshua Kas: Corvus: A Workflow Tool for X-ray and Related Spectroscopies DESCRIPTION:Great strides have been made over the past decade in the theory and calculation of X-ray and related spectra. Some advances involve predictions of material properties such as structure or dynamics in order to make a prediction more complete\, thus requiring less input\, or otherwise reducing the number of free parameters required to fit to experimental data. Other advances\, e.g.\, GW/BSE approaches\, improve common approximations for electron correlation or electron-phonon interactions. However\, many of these advanced methods require a combination of approaches to obtain complete calculations. Thus users must be proficient in a variety of codes\, with multiple input and output formats. Moreover\, users must usually manually link codes by translating the output of one to a format consistent with the input of the next. These aspects of state-of-the-art approaches create barriers to their widespread use and hence reduce the overall quality of theory and analysis methods for X-ray spectra. To address this situation we present Corvus [1\,2]\, a property driven workflow tool designed to combine and execute multiple codes. Corvus interfaces electronic structure\, molecular or crystal structure\, and molecular dynamics or phonon effects\, with end-product codes for calculating spectroscopic quantities such as XAS. Thus Corvus serves to: (1) simplify and unify input and output formats; and (2) automatically create workflows based on target properties and input supplied by a user. The simplification of input/output works through a set of code-specific translation routines to eliminate the need for users to learn a multitude of formats\, while automating the translation of output to be used in the next step in the workflow chain. The automatic generation of workflows sets up a dependency tree for target properties\, which can be filled by user input\, online database search\, or calculations. This allows users to focus on physical properties of interest\, rather than on details of any one calculation step. At present\, translation tools exist for several DFT and MD codes as well as spectroscopy codes. More capabilities will be added as implementation of new code interfaces is relatively easy. We have applied Corvus to a variety of workflows\, for example: structural optimization with ORCA [4]\, followed by calculations of XES and RXES using FEFF [3]; DFT/MD averaged XANES using NWCHEM [5] and FEFF; and FEFF calculations of XAS using ab initio Debye-Waller factors obtained from dynamical matrices provided by ABINIT [6]. Examples of Corvus simplified input\, and automatically generated workflows are presented\, together with results that yield improved agreement in comparison to experiment. \nReferences \n\nS. Story\, Thesis\, http://hdl.handle.net/1773/34136 (2015). \nStory\, S. M.\, Vila\, F. D.\, Kas\, J. J.\, Raniga\, K. B.\, Pemmaraju\, C. D. & Rehr\, J. J. (2019). J. Synchrotron Rad. 26\, 1694-1704. https://doi.org/10.1107/S1600577519007495\nJ.J. Rehr et al.\, Phys. Chem. Chem. Phys.\, 12\, 5503-5513 (2010). https://doi.org/10.1039/b926434e\nF. Neese\, Wiley Interdiscip. Rev. Comput. Mol. Sci. 2\, 73-78 (2012). https://doi.org/10.1002/wcms.81\nM. Valiev et al.\, Comput. Phys. Commun. 181\, 1477 (2010)\,  https://doi.org/10.1016/j.cpc.2010.04.018\nX. Gonze et al.\, Comput. Phys. Commun. 180\, 2582-2615 (2009) https://doi.org/10.1016/j.cpc.2009.07.007 URL:https://xrayabsorption.org/events/journalclub-joshua-kas/ CATEGORIES:XAFS Journal Club END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20200521T090000 DTEND;TZID=America/Los_Angeles:20200521T100000 DTSTAMP:20260416T074906 CREATED:20200512T021354Z LAST-MODIFIED:20200527T123615Z UID:305-1590051600-1590055200@xrayabsorption.org SUMMARY:Jason Shearer: Structural Determination of Small Molecular Systems Using a Wavelet Analysis DESCRIPTION:Presented will be a discussion of efforts to employ a wavelet transform (WT) analysis towards the quantitative structural determination of discrete molecular systems using an EXAFS analysis. Unlike a transition Fourier transform (FT) analysis\, a WT analysis yields a 2D plot in both k- and R-space. Thus\, information contained in k-space that can be lost in a FT analysis is retained. In theory\, this can allow for the unambiguous assignment of different scattering pathways at similar distances\, distinguishing multiple scatterer pathways from single scattering pathways and noise\, and an increase in the resolution between shells. A WT EXAFS analysis has shown utility in the analysis of solid-state periodic samples\, but there has been a paucity of examples of a WT analysis applied to small molecular species in solution. In this talk I will present our initial efforts towards determining the utility of a WT analysis applied towards such systems. Different data analysis strategies will be presented with examples of where we have found both success and “failure” in obtaining structural information using a WT analysis. \nReferences: \n\nPenfold et. al. J. Chem. Phys. 138\, 014104 (2013); https://doi.org/10.1063/1.4772766 \n\n  URL:https://xrayabsorption.org/events/journaclub-jason-shearer/ CATEGORIES:XAFS Journal Club END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20200518T090000 DTEND;TZID=America/Los_Angeles:20200518T100000 DTSTAMP:20260416T074906 CREATED:20200512T020337Z LAST-MODIFIED:20200518T203853Z UID:298-1589792400-1589796000@xrayabsorption.org SUMMARY:Jennifer Mass: MicroXANES studies of pigment degradation in works by Henri Matisse and a Dutch golden age still life DESCRIPTION:The new painting materials used by the Impressionists\, Fauvists\, and Expressionists were critical components of their break with traditional modes of representation. These artists heavily exploited the synthetic organic and inorganic pigments that were newly available as a result of the industrial revolution. However\, the bright and novel hues that made their way onto these artists’ palettes (and in many cases defined the movements listed above) were not always synthesized properly. Pigments in some of the greatest masterpieces of these movements have been found to be highly fugitive or rapidly discolored. These unstable materials can react with adjacent or admixed pigments\, agents of degradation in the environment\, and even the paint binding media surrounding them. The urgent need for preservation of these works calls for intensive materials engineering approaches to identify their mechanisms of degradation and ensure their longevity for future generations. As complex multilayered mesoscale inorganic-organic composites\, these paintings present a wealth of analytical challenges.\nArtists working in this period of the 1880s to the 1920s were aware of the limitations of the materials available to them\, and they attempted to make choices based upon the most stable options at hand. Paint manufacturers were also aware that not all of their offerings were equally stable\, and they would note the stability of the pigments offered for sale. Within this context\, however\, we still have monumental works from this period changing so substantially that they no longer represent the artists’ original vision. Pigments from this period that have been found to alter over time include chrome yellow (PbCrO4.PbSO4)\, zinc yellow (4ZnO.4CrO3\,K2O.3H2O)\, cadmium yellow (CdS)\, emerald green (Cu(C2H3O2)2.3Cu(AsO2)2\, eosin red (C20H8O5Br4\, germanium lake)\, and purpurin (1\,2\,4-trihydroxyantrhaquinone).\nNoninvasive methods for identifying these pigments (both before and after their alteration) including x-ray fluorescence\, hyperspectral imaging\, and ultraviolet-induced infrared fluorescence. To understand their mechanisms of degradation\, however\, requires microscale x-ray diffraction methods (XRD)\, x-ray absorption near edge spectroscopy (XANES) and mapping\, and scanning transmission electron microscopy (STEM) based methodologies such as electron energy loss spectroscopy (EELS). Henri Matisse’s Le Bonheur de vivre (1905-1906) will be used as a case studies to identify highly degraded pigments\, their technologies of manufacture\, and their mechanisms of degradation. Adriaen de Coorte’s Still Life with Five Apricots (1704) will be discussed to probe degradation mechanisms in more traditional artists’ materials. \nReferences: \n\nMass\, J.L.\, Opila\, R.\, Buckley\, B. et al. The photodegradation of cadmium yellow paints in Henri Matisse’s Le Bonheur de vivre (1905–1906). Appl. Phys. A 111\, 59–68 (2013). https://doi.org/10.1007/s00339-012-7418-0\nCotte\, M.\, Susini\, J.\, Dik\, J.\, and Janssens\, K. Synchrotron-Based X-ray Absorption Spectroscopy for Art Conservation: Looking Back and Looking Forward\, Accounts of Chemical Research 43 705-714 (2010). https://doi.org/10.1021/ar900199m\nKeune\, K. et. al  Tracking the transformation and transport of arsenic sulfide pigments in paints: synchrotron-based X-ray micro-analyses J. Anal. At. Spectrom.\, 30\, 813-827 (2015) https://doi.org/10.1039/c4ja00424h\n\n  URL:https://xrayabsorption.org/events/journalclub-jennifer-mass/ CATEGORIES:XAFS Journal Club END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20200514T090000 DTEND;TZID=America/Los_Angeles:20200514T100000 DTSTAMP:20260416T074906 CREATED:20200512T014422Z LAST-MODIFIED:20200516T162413Z UID:294-1589446800-1589450400@xrayabsorption.org SUMMARY:Pieter Glatzel: Reflections on hard X-ray photon-in/photon-out spectroscopy DESCRIPTION:The presentation will be a collection of thoughts that I find interesting for the experimentalist employing hard X-ray photon-in/photon-out spectroscopy with a wavelength dispersive instrument. I would like to draw the attention to some experimental aspects and will give hopefully useful advice that may be considered for the experimental protocol. Furthermore\, I will present the two instruments for X-ray emission spectroscopy at ESRF ID26 and discuss the challenges of a multi-crystal spectrometer. \nReferences:\n[1] Glatzel\, P\, et al. . “Reflections on Hard X-Ray Photon-in/Photon-out Spectroscopy for Electronic Structure Studies” J. Electron Spectros. Relat. Phenomena 2013\, 188\, 17–25; https://doi.org/10.1016/j.elspec.2012.09.004\n[2] Rovezzi\, M\, et al.\,. “High Energy-Resolution x-Ray Spectroscopy at Ultra-High Dilution with Spherically Bent Crystal Analyzers of 0.5 m Radius” Rev. Sci. Instrum. 2017\, 88 (1) 013108 https://doi.org/10.1063/1.4974100;\n[3] M. Rovezzi\, et al.\, “TEXS: in-vacuum tender x-ray emission spectrometer with eleven Johansson crystal analysers.” Journal of Synchrotron Radiation 2020\, 27\, 813. https://doi.org/10.1107/S160057752000243X \n  URL:https://xrayabsorption.org/events/journalclub-pieter-glatzel/ CATEGORIES:XAFS Journal Club END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20200511T090000 DTEND;TZID=America/Los_Angeles:20200511T100000 DTSTAMP:20260416T074906 CREATED:20200512T021026Z LAST-MODIFIED:20200514T015444Z UID:303-1589187600-1589191200@xrayabsorption.org SUMMARY:John Rehr: Fast throughput calculations and the XAFS data base in the Materials Project DESCRIPTION:Modern electronic structure theory and computational methods now permit efficient calculations of ground state properties\, as exemplified by the tabulation of many-thousands of structures in the Materials Project [1]. Complementary advances in the theory of excited states have led to efficient methods for calculations of x-ray and electron spectroscopies\, e.g.\, using the real-space Green’s multiple scattering theory in the FEFF9 code [2]. Here we discuss these developments and how they have been applied to high throughput calculations of x-ray absorption spectra in the Materials Project [3]. In particular\, the world’s largest x-ray database has been constructed\, which currently contains nearly 200\,000 computed K-edge spectra for over 40\,000 materials [4]. Recently this data base has been exploited using Machine-Learning techniques to accurately predict local coordination environments [5]. The database including the FEFF input and output files\, is freely available from the Materials Project [1]. Extensions to L-edge and XAFS spectra are in progress. \nReferences:\n[1] A. Jain et al.\, The Materials Project: A materials genome approach to accelerating materials innovation\, APL Materials 1\, 011002 (2013); https://www.materialsproject.org.\n[2] John J. Rehr et al.\, Parameter-free calculations of X-ray spectra with FEFF9\, Physical Chemistry Chemical Physics 12\, 5503 (2010).\n[3] K. Matthew\, et al.\, High-throughput computational X-ray absorption spectroscopy\, Scientific Data 5\, 180151 (2018).\n[4] Chen Zheng et al.\, Automated generation and ensemble-learned matching of X-ray absorption spectra\, npj Computational Materials 4\, 12 (2018).\n[5] Chen Zheng et al.\, Random Forest Models for Accurate Identification of Coordination Environments from X-Ray Absorption Near-Edge Structure\, Patterns 1\, 100013 (2020). \n  URL:https://xrayabsorption.org/events/journalclub-john-rehr/ CATEGORIES:XAFS Journal Club END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20200507T090000 DTEND;TZID=America/Los_Angeles:20200507T100000 DTSTAMP:20260416T074906 CREATED:20200512T032236Z LAST-MODIFIED:20200512T035931Z UID:319-1588842000-1588845600@xrayabsorption.org SUMMARY:Paul Northrup: The TES Beamline (8-BM) at NSLS-II: tender-energy spatially-resolved X-ray absorption spectroscopy and X-ray fluorescence imaging DESCRIPTION:I will present details of the TES Beamline at the National Synchrotron Light Source II\, covering its design\, commissioning\, and early results. Its scientific mission includes static and in-situ/operando XRF imaging and spatially resolved (microbeam) XAS — in the tender energy range — for characterization of complex heterogeneous\, structured and dynamic natural or engineered materials and systems. My approach for design of TES centered on two primary goals:\n1) optimize for the tender energy range\, which offers access to elements and edges not accessible (or not accessible with optimal performance) at either hard or soft X-ray beamlines.\n2) bring the essential capabilities of an XAS beamline down to the microscale\, so as to measure full EXAFS of a single particle or structure the same size as the probe beam.\nTES offers routine operations from 2.0 to 5.5 keV\, with capabilities to reach down to 1.2 keV with configuration change. It is also designed as an “EXAFS Microprobe” for applications of um-scale extended X-ray absorption spectroscopy fine structure to heterogeneous and small-particle samples. Beam size is user-tunable from ~2 um to 25 um. Energy may be scanned on-the-fly or in step scanning mode. Importantly\, the position of the microbeam at the sample location does not move significantly during energy scanning\, or when changing energy across the entire routine energy range. This enables full EXAFS of a particle or domain the same size as the probe beam\, and measurement of the same spot at different energies. In addition\, there is no measurable drift in energy calibration (repeatability) scan-to-scan and over >24 hours. This is critical in an energy range where simultaneous calibration measurements in transmission are generally not feasible\, and for speciation mapping where precise and stable control of incident energy is essential. The sample environment is helium atmosphere at room pressure\, with infrastructure for in-situ electrochemistry and catalysis in small sample cells or microreactors. \nReferences: \n1) P. Northrup\, 2019. The TES Beamline (8-BM) at NSLS-II\, J. Synch. Rad.\, 26\, 2064-2074 (2019) https://doi.org/10.1107/S1600577519012761 \n2) A Leri\, et al.\, A Marine Sink for Chlorine in Natural Organic Matter\, Nature Geosci.\, 8\, 620-624\, 2015. https://doi.org/10.1038/ngeo2481 \n3) E. Ingall\, et al\, J. Synch. Rad.\, 18\, 189-197. http://journals.iucr.org/s/issues/2011/02/00/hi5614/hi5614.pdf URL:https://xrayabsorption.org/events/journalclub-paul-northrup/ CATEGORIES:XAFS Journal Club END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20200504T090000 DTEND;TZID=America/Los_Angeles:20200504T100000 DTSTAMP:20260416T074906 CREATED:20200512T032509Z LAST-MODIFIED:20200512T035931Z UID:321-1588582800-1588586400@xrayabsorption.org SUMMARY:Faisal Alamgir: Soft and Hard X-ray Operando and In/Ex-situ XAFS: Towards a Unified View of Local Structure and Magnetic Properties in LiMO2 Delafossite Batteries DESCRIPTION:We will look at how electrochemically active materials such as batteries can be studied in a concerted way by tuning to relevant resonant x-ray absorption at both the soft and the hard x-ray energy regimes. We will specifically examine the role of oxygen in the charge compensation of LiMO2 delafossite compounds\, that serve as cathodes for an important class of rechargeable batteries\, and the consequences of such for battery safety and for unprecedented changes to magnetic properties. As a case study of the reactions in LiCoO2\, the electronic and atomic structure local to oxygen was first examined indirectly using hard x-rays by operando resonant Co K-level measurements and was later complemented by operando measurements at the O K-level using soft x-rays. A charge compensation roadmap was established for the LiCoO2 cathodes where we find tandem charge compensation reactions\, first involving oxygen and later by cobalt. The generation of electron holes at oxygen sites explains the transitions in magnetic moment observed in LiCoO2 as a function of de-lithiation. A similar case was found in in the de-lithiation of Li[Ni1/3Co1/3Mn1/3]O2 cathodes. We hope to make the case that a detailed electrochemical roadmap for the reaction mechanisms in LiMO2 cathodes could only be revealed by a combination of soft and hard x-ray based experiments. \nReferences:\nF. M. Alamgir et al.\, LiCoO2 Thin-Film Batteries: Structural Changes and Charge Compensation\, Journal of The Electrochemical Society}\,152\, 5\, (2005) A845. doi: 10.1149/1.1872672 ;\nC. F. Petersburg\, et al\, Oxygen and transition metal involvement in the charge compensation mechanism of LiNi1/3Mn1/3Co1/3O2 cathodes\, J. Mater. Chem.\, 22\, 37\, (2012) 19993-20000;\nC. F. Petersburg\, et al\, Soft X-ray characterization technique for Li batteries under operating conditions\, J. Synchrotron Rad.\, 16\, (2009) 610-615. URL:https://xrayabsorption.org/events/journalclub-faisal-alamgir/ CATEGORIES:XAFS Journal Club END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20200430T090000 DTEND;TZID=America/Los_Angeles:20200430T100000 DTSTAMP:20260416T074906 CREATED:20200512T032821Z LAST-MODIFIED:20200512T035931Z UID:323-1588237200-1588240800@xrayabsorption.org SUMMARY:Frank deGroot: Transition metal K edge spectral shapes: The influence of core hole screening DESCRIPTION:Using High-Energy-Resolution-Fluorescence-Detection (HERFD)\, one can sharpen the pre-edge structures revealing their multiplet nature. In ionic systems\, they can be calculated from the transition from the 3dN ground state to the 1s13dN+1 final state\, where covalent systems need the inclusion of charge transfer effects.[1] The main edge is usually interpreted from the calculation of the transitions to empty states\, using DFT theory\, for example multiple scattering (FEFF). The 1s XPS spectra of transition metal oxides show multiple peaks\, implying that one photon energy gives rise to electrons with multiple kinetic energies. This implies that the 1s XAS spectral shape must be described as the convolution of the empty states with the 1s XPS spectral shape [2]. Isolated transition metal ions only show a pre-edge and an edge\, but bulk oxides show additional intensity between the pre-edge and edge. One can show that this intensity is related to dipole transitions of metal p-character that is part of the 3d-states of a near-neighbour metal ion [3]. X-MCD measurements of CrO2 reveal that the pre-edge is invisible in normal XAS [4]. In systems with two different metal ions one can observe the metal-metal charge transfer in the non-local peaks. [5] \nReferences:\n[1] J. Phys. Cond. Matt. 21\, 104207 (2009).\n[2] Ghiasi et al.\, Phys. Rev. B. 100\, 075146 (2019).\n[3] Juhin et al.\, Phys. Rev. B. 81\, 115115 (2010).\n[4] Zimmermann et al.\, J. Elec. Spec. 222\, 74 (2018).\n[5] Juhin et al. Inorg. Chem. 56\, 10882 (2017). URL:https://xrayabsorption.org/events/journalclub-frank-degroot/ CATEGORIES:XAFS Journal Club END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20200427T090000 DTEND;TZID=America/Los_Angeles:20200427T100000 DTSTAMP:20260416T074906 CREATED:20200512T033137Z LAST-MODIFIED:20200512T035931Z UID:325-1587978000-1587981600@xrayabsorption.org SUMMARY:Eleanor Schofield: X-ray Absorption Spectroscopy in the service of Henry VIII: Conserving a Tudor shipwreck DESCRIPTION:The conservation of marine archaeological wood is complicated by the presence of iron and sulfur. The sulfur originates from sulfate ions in seawater being transformed by sulfur reducing bacteria\, and iron from dissolved fixture and artefacts. Incorporated in to the wood as reduced sulfur/iron compounds\, such as pyrite\, they can become problematic during the drying of the wood as rapid oxidation can result in acid formation which can promote degradation. The Mary Rose was a 16th century Tudor warship\, commissioned by Henry VIII. After 34 years sailing\, the ship sank off the coast of Portsmouth in 1545. Rediscovered in the late 1960s\, the remaining hull emerged from the Solent in 1982 and now resides in a purpose built museum in Portsmouth Historic. In 2013 the consolidation treatment of the wood\, to compensate for degradation\, was completed and an air drying process commenced. During this phase samples have been periodically taken to monitor the evolution of iron and sulfur as a function of drying time using X-ray Absorption Spectroscopy. Alongside this Fourier-Transform Infrared Spectroscopy has been used to correlate any observed changes to the degradation levels within the wood. This information is crucial in understanding the chemical state of the wood and designing future conservation strategies. \nReferences:\n1. Schofield\, E. J.\, “Illuminating the past: X-ray analysis of our cultural heritage” Nat. Rev. Mater. 3\, 285-287\, 2018\n2. Schofield\, E. J.\, Sarangi\, R.\, Mehta\, A.\, Jones\, A. M. and Chadwick\, A. V. “Nanotechnology and Synchrotron light in the service of Henry VIII: preserving the Mary Rose” Materials Today\, Vol 14 (7-8) Pages: 354-358 2011\n3. M. Sandström\, F. Jalilehvand\, I Persson\, U. Gelius\, P. Frank\, I. Hall-Roth\, Nature 2002\, 415\, 893–897. URL:https://xrayabsorption.org/events/journalclub-eleanor-schofield/ CATEGORIES:XAFS Journal Club END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20200423T090000 DTEND;TZID=America/Los_Angeles:20200423T100000 DTSTAMP:20260416T074906 CREATED:20200512T033410Z LAST-MODIFIED:20200512T035931Z UID:327-1587632400-1587636000@xrayabsorption.org SUMMARY:Joe Fowler: X-ray Fluorescence Line Metrology for the 21st Century DESCRIPTION:Databases of x-ray fluorescence line energies such as those of Deslattes (2003) and Bearden (1967) are critical to the calibration of any analytical tools that identify elemental compositions by their x-ray “fingerprints.” To be useful\, such tables have to favor completeness over accuracy. Unfortunately\, a full 75% of the lines in the current NIST database (SRD-128) rely on measurements at least 50 years old\, coming from an age when the SI meter and the x-ray wavelength had never been tied together. Worse\, SRD-128 lacks all information about line shapes or any M lines whatsoever. At NIST\, we have begun a program to measure as many lines as possible with transition-edge sensor (TES) microcalorimeters\, starting with the hard x-ray L lines of certain lanthanide metals. As Kelsey Morgan described on March 30\, a TES combines advantages of solid-state detectors and diffractometers: it measures an enormous spectral region at once with resolving power of 1000 or higher. In tandem\, we have also rejuvenated the SI-traceable diffractometer of Deslattes’ team\, in order to expand the limited set of lines available for calibration of the TES spectrometer. \nhttps://arxiv.org/abs/1702.00507 and https://arxiv.org/abs/1511.03950 URL:https://xrayabsorption.org/events/journalclub-joe-fowler/ CATEGORIES:XAFS Journal Club END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20200420T090000 DTEND;TZID=America/Los_Angeles:20200420T100000 DTSTAMP:20260416T074906 CREATED:20200512T033612Z LAST-MODIFIED:20200512T035931Z UID:329-1587373200-1587376800@xrayabsorption.org SUMMARY:Rene Bes: Nuclear fuel study using XAS: benefits of HERFD for U valence states evaluation DESCRIPTION:The safe use and disposal of UO2 based nuclear fuels relies on the stability of their material properties\, under extreme conditions of temperature and irradiation\, and with constantly evolving chemical composition. Among them\, the uranium valence state’s behavior is at the heart of safety assessment during the entire fuel lifecycle. First\, the oxidation from UO2 to UO3 induces for example considerable reorganization of the crystal structure and results in a volume expansion of about 36% when reaching the U3O8 intermediate state\, eventually leading to fuel cladding failure. Secondly\, the uranium valence state U6+ and to a lesser extent U5+ are known to have solubility several orders of magnitude higher than U4+\, which is a critical parameter during fuel final disposal\, the UO2 matrix very slow dissolution acting as the ultimate barrier of radioactivity release into the environment. X-ray absorption spectroscopy (XAS) is a key technique to assess U valence states in nuclear fuels thanks to its elemental sensitivity. However\, XAS applied to nuclear fuels suffers from the presence of almost all the periodic table in spent fuel\, from the high radioactive background limiting the number of available beamlines\, from the fact that transmission mode is often impossible to perform\, and from the large core-hole broadening effects. I will discuss how High Energy Resolution Fluorescence Detected XAS (HERFD-XAS) can help overcoming those drawbacks through a selection of a few recent examples\, and I will describe the main benefits of HERFD for U valence state evaluation. \nReferences:\nK. O. Kvashnina\, S. M. Butorin\, P. Martin\, and P. Glatzel\, Phys. Rev. Lett. 111 (2013) 253002 http://dx.doi.org/10.1103/PhysRevLett.111.253002 ;\nR. Bès\, M. Rivenet\, P.-L. Solari\, K. O. Kvashnina\, A. C. Scheinost\, and P. M. Martin\, Inorg. Chem. 55 (2016) 4260-4270 http://dx.doi.org/10.1021/acs.inorgchem.6b00014 ;\nG. Leinders\, R. Bès\, J. Pakarinen\, K. Kvashnina\, and M. Verwerft\, Inorg. Chem. 56 (2017) 6784−6787 http://dx.doi.org/10.1021/acs.inorgchem.7b01001;\nG. Leinders\, R. Bès\, K. Kvashnina\, and M. Verwerft\, Inorg. Chem. 59 (2020) 4576−4587 https://dx.doi.org/10.1021/acs.inorgchem.9b03702 URL:https://xrayabsorption.org/events/journalclub-rene-bes/ CATEGORIES:XAFS Journal Club END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20200416T090000 DTEND;TZID=America/Los_Angeles:20200416T100000 DTSTAMP:20260416T074906 CREATED:20200512T033955Z LAST-MODIFIED:20200512T035931Z UID:332-1587027600-1587031200@xrayabsorption.org SUMMARY:Yulia Pushkar: X-ray Emission Spectroscopy at X-ray Free Electron Lasers: Limits to Observation of Unperturbed Electronic Structures DESCRIPTION:Modern free electron lasers provide intense X-ray pulses with 10^12 photons within ~10-100 femtoseconds. Such pulses enable new experimental techniques and provide unique opportunities for investigation of electronic and nuclear dynamics on their intrinsic time-scales. Interaction of ultra-bright\, ultra-short X-ray pulses with matter can induce a multitude of nonlinear excitation processes which must be carefully considered when planning spectroscopic measurements and interpreting data recorded at XFELs. In most cases correct interpretation of the spectroscopic response and analysis of the electronic structure hinges on the assumption of single photon excitations. Here we attempted to answer the fundamental question on the limits to probing the ground (or native) electronic structure of a 3d transition metal ion at XEFL sources. Ions of the 3d transition metal\, e.g.\, Mn(II)\, in a lighter element (O\, C\, H) environment were used as a model system. X-ray emission spectroscopy recorded from Mn2+ at different pulse conditions demonstrate spectral changes as a function of increased pulse intensity and pulse duration. To explain these changes\, we develop a rate equation based on sequential ionization and relaxation events forming multiply ionized states during a single pulse which agree with observed spectroscopic trends. The percentage of Mn Kbeta emission recorded after the 1st\, 2nd and 3rd 1s ionization events is calculated from the developed rate equation model and validated by experimental measurements. A method for estimating shifts in atomic X-ray emission lines from sequential ionization during a single XFEL pulse is given. From our data we infer that\, in addition to multiple ionization\, the impact of electron cascades is more significant for longer pulses. We note that while use of shorter X-ray pulses will help to counteract additional effects of electron cascades it will not help to overcome the spectral shifts due to sequential ionization. Presented data and associated analysis will help with experimental designs at current and upcoming XFELs where even higher intensities and shorter pulses are expected. 3d elements have a variety of important applications such as in bio-inorganic catalysis\, chemical catalysis and energy storage / conversion making robust protocols for their XFEL analysis of general importance. \nhttp://dx.doi.org/10.1021/acs.jpclett.8b03595 URL:https://xrayabsorption.org/events/journalclub-yulia-pushkar/ CATEGORIES:XAFS Journal Club END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20200413T090000 DTEND;TZID=America/Los_Angeles:20200413T100000 DTSTAMP:20260416T074906 CREATED:20200512T034144Z LAST-MODIFIED:20200512T035931Z UID:334-1586768400-1586772000@xrayabsorption.org SUMMARY:Jacinto Sa: Solving chemical mechanisms with X-ray spectroscopy DESCRIPTION:As a scientist have been always fascinated with how chemical systems react and interact with the natural world. Spectroscopy is a great tool to look at systems in real-time and operation conditions. Hard X-ray photon-in photon-out spectroscopy offers great possibilities due to its chemical sensitivity and speciation as well as high penetration. In this webinar\, I will talk about two chemical processes and the developments in X-ray spectroscopy that made the studies possible. My studies have been made possible with the development of the dispersive von Hamos-type spectrometer (1)\, which enabled us to perform high-resolution studies on real systems due to its simple and versatile geometry. The first case study is called atomic telemetry\, a method that enables us to follow chemotherapy drugs action mechanism under physiological conditions. The methodology was validated with a known drug (cisplatin) but in this webinar\, I will present the findings from a drug (Pt-103) with an unknown action mechanism (2). The second case relates to the understanding of plasmonic materials hot carrier formation\, and their importance to solar applications. Using synchrotron radiation and HR-XAS we were able to demonstrate for the first time the formation of hot electrons (3). However\, to address their dynamics one needed to develop a way to perform RIXS measurements at the XFEL with the shortest and most intense X-ray pulses. I will show how we can do that (4) and what we plan to do with this methodology. \nReferences: (1 ) J. Szlachetko et al. Rev. Scie. Instrum. 2012\, 83\, 103105 https://doi.org/10.1063/1.4756691 (2 ) J. Czapla-Masztafiak et al. J. Phys. Chem. Lett. 2017\, 8\, 805-811 https://doi.org/10.1021/acs.jpclett.7b00070 (3) J. Sá\, et al. Energy Scie. Technol. 2013\, 6\, 3584-3588 https://doi.org/10.1039/C3EE42731E (4) Y. Kayser et al. Nat. Commun. 2019\, 10\, 4761 https://doi.org/10.1038/s41467-019-12717-1 URL:https://xrayabsorption.org/events/jacinto-sasolving-chemical-mechanisms-with-x-ray-spectroscopy/ CATEGORIES:XAFS Journal Club END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20200409T090000 DTEND;TZID=America/Los_Angeles:20200409T100000 DTSTAMP:20260416T074906 CREATED:20200512T034432Z LAST-MODIFIED:20200512T035932Z UID:337-1586422800-1586426400@xrayabsorption.org SUMMARY:Neil Hyatt: Multimodal microfocus XAS to understand and remediate DU munitions contamination DESCRIPTION:The talk will show how multimodal microfocus X-ray spectroscopy has been applied to characterize depleted uranium particles from munitions testing to predict and understand their environmental behavior. A combination of spatially resolved XRD\, XRF and XAS techniques\, combined with laboratory SEM observations\, is shown to effectively differentiate DU particulate contamination in near surface and burial sites\, and provide evidence of particulate alteration. This knowledge was used to design and understanding more effective remediation measures for depleted uranium contamination\, with multimodal characterisation supporting process optimisation. \nReferences:\nCrean et al.\, Environ. Sci. Tech.\, 2014\, 48\, 1467; https://doi.org/10.1021/es403938d \nCrean et al.\, J. Haz. Mat.\, 2013\, 263\, 382. https://doi.org/10.1016/j.jhazmat.2013.08.013 URL:https://xrayabsorption.org/events/journalclub-neil-hyatt/ CATEGORIES:XAFS Journal Club END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20200406T090000 DTEND;TZID=America/Los_Angeles:20200406T100000 DTSTAMP:20260416T074906 CREATED:20200512T034629Z LAST-MODIFIED:20200512T035932Z UID:339-1586163600-1586167200@xrayabsorption.org SUMMARY:Steve Heald: Sector 25 at the APS-U: Two new beamlines for advanced spectroscopy DESCRIPTION:As part of the Advanced Photon Source (APS) Multibend Achromat lattice upgrade two new beamlines for spectroscopy will be constructed on a canted undulator source at Sector 25. The programs at the 20-ID beamline at the APS need to move to sector 25 to make room for a planned long beamline. These will be combined with some other APS spectroscopy programs at sector 25 to use two new beamlines on a canted undulator. These two beamlines will service existing and upgraded endstations covering a variety of spectroscopy applications. There will be a microprobe branch that will provide sub-micron beams for fluorescence imaging\, and micro-XAFS. These can be combined with confocal optics for micron level depth sensitivity. This branch will also have a station for XAFS experiments requiring a high-brilliance high-flux beam such as doped thin films or ultra-dilute samples. The second Advanced Spectroscopy branch will provide beam to two inline hutches. The first will have stations for both an enhanced LERIX spectrometer for non-resonant inelastic scattering (x-ray Raman)\, and spectrometers for high resolution emission spectroscopy. The second hutch will provide space for experiments requiring extensive setup\, such as time-resolved pump-probe experiments. Both hutches will have a variety of focusing options providing beam sizes down to a few microns. To provide greater beam separation\, both lines will have side deflecting mirrors for harmonic rejection\, and focusing/collimation. The planned energy ranges are 4-32 keV for the microprobe branch\, and 4-40 keV for the Advanced Spectroscopy branch. The horizontal deflection mirrors allow use of small offset monochromators equipped with liquid nitrogen cooled Si (111) crystals for monochromatic beam\, and wide-bandpass multilayers providing higher flux for experiments that do not need high resolution such as imaging and non-resonant emission spectroscopy. The Advanced Spectroscopy branch will also have a secondary monochromator for experiments needing better resolution than provided by Si (111). URL:https://xrayabsorption.org/events/journalclub-steve-heald/ CATEGORIES:XAFS Journal Club END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20200402T090000 DTEND;TZID=America/Los_Angeles:20200402T100000 DTSTAMP:20260416T074906 CREATED:20200512T034838Z LAST-MODIFIED:20200512T035932Z UID:341-1585818000-1585821600@xrayabsorption.org SUMMARY:Martin McBriarty: Top-Down Approaches to EXAFS Analysis DESCRIPTION:EXAFS spectra are often modeled using a small number of virtual coordination shells which can vary in coordination number\, bond length\, and disorder. While this bottom-up approach is generally successful for single-phase samples\, it becomes intractable when the element of interest occupies multiple complex coordination states. Such cases may require a top-down approach\, in which the measured spectrum is fitted using models with fixed atom positions and disorder. Given reasonable starting assumptions\, such as ab initio molecular dynamics (AIMD) simulations of each possible component of the sample\, the actual coordination states can be identified and quantified. I will present two examples of top-down solutions to difficult EXAFS problems: (1) the mechanisms of uranium incorporation into iron (oxyhydr)oxide minerals\, and (2) the distribution of crystal phases in ferroelectric HfO2/ZrO2 nanostructures \nhttps://onlinelibrary.wiley.com/doi/full/10.1002/pssb.201900285 https://pubs.acs.org/doi/abs/10.1021/acs.est.8b00297 URL:https://xrayabsorption.org/events/journalclub-martin-mcbriarty/ CATEGORIES:XAFS Journal Club END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20200330T090000 DTEND;TZID=America/Los_Angeles:20200330T100000 DTSTAMP:20260416T074906 CREATED:20200512T035015Z LAST-MODIFIED:20200512T035932Z UID:343-1585558800-1585562400@xrayabsorption.org SUMMARY:Kelsey Morgan: Hot science with cool sensors DESCRIPTION:The transition-edge sensor (TES) microcalorimeter uses the sharply temperature-dependent resistance of the superconducting transition to measure the energy of X-ray and gamma ray photons. A single TES is a broadband\, energy-dispersive area detector capable of eV-scale energy resolution with good quantum efficiency. With an array of hundreds or thousands of sensors\, a TES-based spectrometer can have orders of magnitude higher throughput than wavelength dispersive instruments. In this talk\, I will introduce the basic principles of TES operation\, and discuss how they are exploited to design sensors with resolving power R > 1000 at a wide range of photon energies\, from soft X-rays to gamma rays. This capability makes the TES a powerful tool for PFY-XAFS\, RIXS\, and time-resolved XES/XAS measurements\, particularly for weak sources or for highly dilute or radiation-sensitive samples. I will provide a brief overview of the TES spectrometers that are currently available to the X-ray science community\, and then highlight some exciting new instruments that are currently under development. \nhttps://physicstoday.scitation.org/doi/full/10.1063/PT.3.3995 URL:https://xrayabsorption.org/events/journalclub-kelsey-morgan/ CATEGORIES:XAFS Journal Club END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20200326T090000 DTEND;TZID=America/Los_Angeles:20200326T100000 DTSTAMP:20260416T074906 CREATED:20200512T035155Z LAST-MODIFIED:20200512T035932Z UID:345-1585213200-1585216800@xrayabsorption.org SUMMARY:Adam Hitchcock: Soft X-ray Spectromicroscopy in Scanning Transmission X-ray Microscopes DESCRIPTION:Soft X-ray scanning transmission microscopy (STXM) is a powerful tool for nanoscale materials analysis\, with significant advantages over analytical electron microscopies for studies of radiation sensitive materials. Chemical species identified by near edge X-ray absorption fine structure (NEXAFS) spectra can be mapped quantitatively in 2D and in 3D. STXM instrumentation and methods will be described\, with emphasis on spectromicroscopy: chemical mapping by the analysis of images measured at many photon energies. Performance will be illustrated by recent studies of (i) cathodes of low temperature\, proton exchange membrane fuel cells (PEM-FC)\, which are under development for automotive applications\, and (ii) biomineralization of single domain\, single crystal nano-magnetite by magnetotactic bacteria. \nReferences: https://doi.org/10.1016/j.elspec.2015.05.013 and https://doi.org/10.1016/j.jpowsour.2018.01.074 and https://doi.org/10.1016/j.chemgeo.2019.119348 URL:https://xrayabsorption.org/events/journalclub-adam-hitchcock/ CATEGORIES:XAFS Journal Club END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20200323T090000 DTEND;TZID=America/Los_Angeles:20200323T100000 DTSTAMP:20260416T074906 CREATED:20200512T035351Z LAST-MODIFIED:20200512T035932Z UID:347-1584954000-1584957600@xrayabsorption.org SUMMARY:Evan Jahrman Core-to-core X-ray Emission Spectroscopy: Pitfalls and Advantages for Lab-based and Synchrotron Users DESCRIPTION:Core-to-core X-ray emission spectroscopy (CTC-XES) has not only provided key insights into atomic physics but is extremely well positioned to serve as a major analytical technique for several materials systems in the coming decades. Moreover\, CTC-XES frequently serves as an enabling phenomenon for more exotic varieties of synchrotron-based XAFS. I will cover several applications of CTC-XES and explain the origin and shape of commonly observed spectral features. I intend to make this talk both a pleasant refresher for seasoned X-ray physicists and useful to graduate students preparing to embark on their own materials characterization campaigns. \nReferences: https://doi.org/10.1103/PhysRevB.50.11347 and\nhttps://doi.org/10.1021/acs.analchem.8b00302 URL:https://xrayabsorption.org/events/journalclub-evan-jahrman/ CATEGORIES:XAFS Journal Club END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20200319T090000 DTEND;TZID=America/Los_Angeles:20200319T100000 DTSTAMP:20260416T074906 CREATED:20200512T035516Z LAST-MODIFIED:20200512T035557Z UID:349-1584608400-1584612000@xrayabsorption.org SUMMARY:Simo Huotari: X-ray Raman spectroscopy: glimpse of the state of the art for samples in complex environments DESCRIPTION:In this lecture I will continue where the previous lecture ends and talk about some examples of how XRS is used to study materials under high pressure and chemical reactions. \nReferences: https://www.nature.com/articles/nmat3031 and https://pubs.acs.org/doi/abs/10.1021/jp912208v URL:https://xrayabsorption.org/events/journalclub-simo-huotari/ CATEGORIES:XAFS Journal Club END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20200318T090000 DTEND;TZID=America/Los_Angeles:20200318T100000 DTSTAMP:20260416T074906 CREATED:20200512T035717Z LAST-MODIFIED:20200512T035717Z UID:351-1584522000-1584525600@xrayabsorption.org SUMMARY:Jerry Seidler: What is X-ray Raman Scattering\, and What Did Raman Have to Do With It? DESCRIPTION:X-ray Raman Scattering (XRS\, often also called nonresonant inelastic x-ray scattering)\, is a hard x-ray alternative to soft x-ray NEXAFS. I’ll review the basic physics\, including the role of momentum transfer to tune selection rules. And I’ll explain Raman’s involvement\, or lack thereof. \nReferences:\nhttps://journals.aps.org/prb/abstract/10.1103/PhysRevB.74.214117 and https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.105.053202 URL:https://xrayabsorption.org/events/journalclub-jerry-seidler_mar2020/ CATEGORIES:XAFS Journal Club END:VEVENT END:VCALENDAR