Combination of X-ray synchrotron radiation techniques to gather information for clinicians

International audienceAmong the different techniques specific to synchrotron radiation, the combination of X-ray absorption spectroscopy with X-ray scattering experiments is a powerful tool to characterize samples with a capability to gather structural and electronic information at the cellular level. In the present contribution, selected examples making use of such techniques, point out as well the information that one can have access to. Via the presentation of the physicochemical data, this paper focuses on displaying the information that has a significant clinical character

Visualizing mineralization processes and fossil anatomy using synchronous synchrotron X-ray fluorescence and X-ray diffraction mapping

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Trace elements discriminate between tissues in highly weathered fossils

Palaeontologists assess the affinities of fossils using either morphology-based phylogenetic analyses, possibly enhanced by the use of advanced imaging techniques, or the identification of remnants or derivatives of fossil organic molecules with high taxonomic specificity (“biomarkers”). However, these approaches are often of little use for the majority of fossils whose original morphology and chemistry have been severely altered or completely lost during decay, diagenesis and modern weathering. Here we show that the inorganic incorporation of trace elements during fossilization and diagenesis can be used to assess the affinity of highly altered fossils, constituting a powerful tool overlooked so far. This is illustrated by the study of a wide range of animals from the Early Ordovician Fezouata Shale (Tremadocian, Morocco) using synchrotron X-ray fluorescence major-to-trace elemental mapping. Although all fossils studied here have turned into iron oxides, spectral analyses reveal that their different tissue types (i.e. biomineralised, sclerotised, cuticularised, and internal tissues) can be distinguished on the basis of their trace element inventories. The resulting elemental classes and distributions allowed us to identify an enigmatic, highly weathered organism as a new stem euarthropod preserving remains of its nervous system

De Colorando Auro: Medieval colouring techniques researched using modern analytical techniques

The visual appearance of gold and gilding can be influenced in many ways, such as by changing the composition of the gold alloy or the nature of the gilded substrate. A less known medieval technique, reported in historical treatises, is the chemical treatment of the gilded surface itself, after application and burnishing of the gilding. We reporte here results regarding the study of the Holy Lady Shrine of Huy (13th c AD Mosan, Belgium) on which a possible artificial colouration of the gildings was detected. This led to many questions regarding applicable conservation-restoration treatments. Here is an overview of the results obtained, along with a discussion of the methodology that was developed to study this colouration process, also highlighting the necessary complementarity between laboratory and synchrotron-based analytical approaches. The 3-steps methodology proposed in this paper is generic for most cultural heritage problems where the application of ancient surface modification recipes is suspected but where the scarcity of the historical samples does not allow a direct study of such samples.L’aspect visuel de l’or et des dorures peut être modifié de diverses manières, notamment en changeant la composition de l’alliage ou la nature du support doré. Une technique médiévale moins connue, évoquée dans les traités anciens, consiste à provoquer une réaction chimique après application et brunissage de la dorure. Les recherches sur la châsse de Notre-Dame de Huy (art mosan du xiiie siècle) ont révélé une possible coloration artificielle des dorures. Cette découverte soulève de nombreuses questions quant aux traitements de conservation-restauration utilisables. Nous présentons ici un exposé sommaire des résultats obtenus ainsi qu’un compte rendu de la méthode mise au point pour étudier ce procédé de coloration, en soulignant la complémentarité indispensable entre les examens de laboratoire et l’analyse par rayonnement synchrotron. Dans les sciences du patrimoine culturel, cette méthode en trois temps concerne la plupart des situations où une recette ancienne semble avoir été employée pour modifier la surface, mais où la rareté des échantillons historiques ne permet pas l’étude directe de sous-échantillons

Relevance of the Formation of Intermediate Non-Equilibrium Phases in YBa2Cu3O7-x Film Growth by Transient Liquid-Assisted Growth

Transient liquid-assisted growth (TLAG) is a non-equilibrium ultrafast method to grow YBa2Cu3O7–x (YBCO) superconducting films at up to 100 nm/s using chemical solution deposition. In this work, we study the formation of non-equilibrium crystalline intermediate phases prior to the growth of YBCO through TLAG. We analyze the thermal decomposition and microstructural evolution of a propionate-based fluorine-free solution used as precursor to YBCO epitaxial films. Thermal analyses (TGA, DSC), coupled with techniques to monitor the volatiles (TG-IR), were applied in situ during film pyrolysis in humid O2, while the thermal evolution of the solid residue was characterized by infrared spectroscopy and X-ray diffraction, both ex situ and in situ in synchrotron radiation sources, and by scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS) cross-sectional analysis. Unexpected effects, observed during the decomposition of the ternary solution, are the formation of intermediate non-equilibrium phases: Cu2O or Cu(0) and monoclinic BaCO3. We emphasize that working with anhydrous solutions and anhydrous deposition conditions promotes the formation of the expected equilibrium phases. Finally, in situ X-ray diffraction permits monitoring the influence of the non-equilibrium monoclinic BaCO3 phase on the formation of binary oxide phases, precursors of TLAG YBCO film growth. Understanding the evolution of non-equilibrium phases is shown to be fundamental for the control of the final YBCO film’s microstructure and performance, since the latter are strongly affected by the film’s thermal history after solution deposition.This work was funded by Ministerio de Ciencia, Innovation y Universidades (RTI2018-095853-B-C21 and RTI2018-095853-B-C22) cofinanced by the European Regional Development Fund, and the EU Ultrasupertape project (ERC ADG-2014-669504). We also acknowledge the Center of Excellence Severo Ochoa (SEV-2015-0496), the Generalitat de Catalunya (2017-SGR-1519) and the COST -action NANOCOHYBRI (CA16218). In situ FTIR experiments were performed at the MIRAS beamline of the ALBA Synchrotron with the collaboration of ALBA staff. We also thank the DiffAbs beamline at SOLEIL Synchrotron facility and the beamline staff support for the in situ XRD experiments. We thank the ICMAB, INA-Zaragoza and UdG scientific services and technical staff for the support on the experiments. S.R. thanks the Universitat de Girona (UdG) for the IFUdG grant. L.S. and J.J. also acknowledge their FPU-MINECO PhD grant.Peer reviewe

Kinetic Control of Ultrafast Transient Liquid Assisted Growth of Solution-Derived YBa2Cu3O7-x Superconducting Films

Transient liquid assisted growth (TLAG) is an ultrafast non-equilibrium growth process mainly governed by kinetic parameters, which are only accessible through fast in situ characterizations. In situ synchrotron X-ray diffraction (XRD) analysis and in situ electrical resistivity measurements are used to derive kinetic diagrams of YBa2 Cu3 O7- x (YBCO) superconducting films prepared via TLAG and to reveal the unique peculiarities of the process. In particular, diagrams for the phase evolution and the YBCO growth rates have been built for the two TLAG routes. It is shown that TLAG transient liquids can be obtained upon the melting of two barium cuprate phases (and not just one), differentiated by their copper oxidation state. This knowledge serves as a guide to determine the processing conditions to reach high performance films at high growth rates. With proper control of these kinetic parameters, films with critical current densities of 2-2.6 MA cm-2 at 77 K and growth rates between 100-2000 nm s-1 are reached. These growth rates are 1.5-3 orders of magnitude higher than those of conventional methods.The authors acknowledge the European Research Council for the ULTRASUPERTAPE project (ERC-2014-ADG-669504), IMPACT project (ERC-2019-PoC-874964) and EU COST action for CA16218 (NANOCOHYBRI). The authors also acknowledge financial support from Spanish Ministry of Science and Innovation with PID2021-127297OB-C21 and PID2021-127297OB-C22, and from Spanish Ministry of Science, Innovation and Universities through the “Severo Ochoa” Program for Centers of Excellence in R&D (SEV-2015-0496 and CEX2019-000917-S), and from the Spanish Ministry of Economy and Competitiveness with the SUMATE project (RTI2018-095853-B-C21, RTI2018-095853-B-C22, co-financed by the European Regional Development Fund, MCIU/AEI/FEDER, UE). They also thank the Catalan Government (2017-SGR-1519) and the Catalan energy network XRE4S (2018 XARDI 00002) for their support. L.S., D.G., and A.K. acknowledge financial support from Spanish Ministry of Science, Innovation and Universities through the FPI grant PRE2019-090621, PRE2018-084537, and PRE2020-091817, respectively. L.So. and J.J. acknowledge financial support from Spanish Ministry for the FPU grants. S.R. thanks the Universitat de Girona for IFUdG grant and A.Q. thanks the Spanish Ministry of Science, Innovation and Universities (“Juan de la Cierva” postdoctoral fellowship [Grant no. IJC2018-035034-I]). The authors thank the Scientific Services at ICMAB and ICN2 Electron Microscopy Division. The authors acknowledge the use of instrumentation as well as the technical advice provided by the National Facility ELECMI ICTS, node “Laboratorio de Microscopías Avanzadas” at University of Zaragoza. The authors also acknowledge SOLEIL Synchrotron for provision of synchrotron radiation facilities and are grateful for assistance while using the DiffAbs beamline.With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).Peer reviewe

CROISSANCE, STRUCTURE ET MAGNETISME DE FILMS METALLIQUES SUPPORTES PAR DES OXYDES POLAIRES

GRENOBLE1-BU Sciences (384212103) / SudocSudocFranceF