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1. The iron record of asteroidal processes in carbonaceous chondrites

Author

Garenne, A., Beck, P., Montes-Hernandez, G., Bonal, L., Quirico, E., Proux, O., and Hazemann, J. L.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

The valence of iron has been used in terrestrial studies to trace the hydrolysis of primary silicate rocks. Here, we use a similar approach to characterize the secondary processes, namely thermal metamorphism and aqueous alteration, that have affected carbonaceous chondrites. X-ray absorption near-edge structure spectroscopy at the Fe-K- edge was performed on a series of 36 CM, 9 CR, 10 CV, and 2 CI chondrites. Among the four carbonaceous chondrites groups studied, a correlation between the iron oxidation index (IOI = [2 ((Fe2+) + 3(Fe3+))/FeTOT) and the hydrogen content is observed. However, within the CM group, for which a progressive alteration sequence has been defined, a conversion of Fe3+ to Fe2+ is observed with increasing degree of aqueous alteration. This reduction of iron can be explained by an evolution in the mineralogy of the secondary phases. In the case of the few CM chondrites that experienced some thermal metamorphism, in addition to aqueous alteration, a redox memory of the aqueous alteration is present: a significant fraction of 3+ 2+ 0 Fe is present, together with Fe and sometimes Fe. From our data set, the CR chondrites show a wider range of IOI from 1.5 to 2.5. In all considered CR chondrites, the three oxidation states of iron coexist. Even in the least-altered CR chondrites, the fraction of Fe3+ can be high (30% for MET 00426). This observation confirms that oxidized iron has been integrated during formation of fine-grained amorphous material in the matrix. Last, the IOI of CV chondrites does not reflect the reduced/oxidized classification based on metal and magnetite proportions, but is strongly correlated with petrographic types. The valence of iron in CV chondrites therefore appears to be most closely related to thermal history, rather than aqueous alteration, even if these processes can occur together .

Published
2020
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3. In situ X-ray absorption spectroscopy using the FAME autoclave: a window into fluid-mineral-melt interactions in the Earth's crust.

Author

Testemale, D., Pokrovski, G. S., Lahera, E., Prat, A., Kieffer, I., Delnet, W., Proux, O., Louvel, M., Sanchez-Valle, C., and Hazemann, J. L.

Subjects
CHEMICAL speciation, SILICATE minerals, X-ray absorption, X-ray spectroscopy, X-ray fluorescence
Abstract

We discuss the X-ray absorption spectroscopy (XAS) methods elaborated using the high pressure and high-temperature autoclaves installed at FAME and FAME-UHD beamlines. These methods are based on the in situ acquisition of X-ray transmission and fluorescence spectra of hydrothermal fluids and silicate melts and enable the derivation of both solubility and speciation information about metal complexes. The technological assets of our autoclaves are described across a wide range of experimental conditions spanning from different types of hydrothermal fluids, from liquid-like to vapor-like densities having metal concentrations of <1–10,000 ppm, to magmatic fluid-melt systems at 1000°C. Scientific examples are presented to illustrate the use and the advantages of our spectroscopic 'micro-batch' reactors. Finally, the integration of our autoclave setups on the FAME-UHD crystal analyzer spectrometer and the benefits of this technique are demonstrated. [ABSTRACT FROM AUTHOR]

Published
2024
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4. Modelling the Pb release during Portland cement alteration

Author

Benard, A., Rose, J., Hazemann, Jean-Louis, Proux, O., Trotignon, L., Borschneck, D., Nonat, A., Chateau, L., and Bottero, J. -Y.

Subjects
Condensed Matter - Materials Science
Abstract

Complex cementitious matrices undergo weathering with environmental exchange and can release metallic pollutants during alteration. The molecular mechanisms responsible for metal release are difficult to identify, though this is necessary if such processes are to be controlled. The present study determines and models the molecular mechanisms of Pb release during Portland cement leaching. As Pb release is strongly related to its speciation (i.e. atomic environment and the nature of bearing phases), the first objective of the present study was to investigate the evolution of Pb retention sites together with the evolution of the cement mineralogy during leaching. Complementary and efficient investigation tools were used, namely X-ray diffraction, micro-X-ray fluorescence and X-ray absorption fine structures. The second objective was to reproduce our results with a reactive transport code (CHESS/HYTEC) in order to test the proposed speciation model of Pb. Combined results indicate that in both the unaltered core and the altered layer of the leached cement, Pb(II) would be retained through C-S-H 'nano-structure', probably linked to a Q1 or Q2P silicate tetrahedra. Moreover in the altered layer, the presence of Fe atoms in the atomic environment of Pb is highly probable. Unfortunately little is known about Fe phases in cement, which makes the interpretation difficult. Can Fe- substituted hydrogranet (C3AH6) be responsible for Pb retention? Modelling results were consistent with Pb retention through C-S-H in layers and also in an additional, possibly Fe-containing, Pb-retention phase in the altered layer.

Published
2014
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5. Emergence of ferromagnetism and Jahn-Teller distortion in low Cr-substituted LaMnO3

Author

Ramos, A. Y., Tolentino, H. C. N., Bunau, O., Joly, Y., Grenier, S., Souza, R. A., Souza-Neto, N. M., Baudelet, F., Wilhelm, F., Rogalev, A., Proux, O., and Caneiro, A.

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

The emergence of a ferromagnetic component in $LaMnO_{3}$ with low Cr-for-Mn substitution has been studied by x-ray absorption spectroscopy and x-ray magnetic circular dichroism at the Mn and Cr K edges. The local magnetic moment strength for the Mn and Cr are proportional to each other and follows the macroscopic magnetization. The net ferromagnetic components of $Cr^{3+}$ and $Mn^{3+}$ are found antiferromagnetically coupled. Unlike hole doping by La site substitution, the inclusion of $Cr^{3+}$ ions up to x = 0.15 does not decrease the Jahn-Teller (JT) distortion and consequently does not significantly affect the orbital ordering. This demonstrates that the emergence of the ferromagnetism is not related to JT weakening and likely arises from a complex orbital mixing., Comment: 5 figures

Published
2013
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7. Hard x-ray spectroscopy in NaxCoO2 and superconducting NaxCoO2 - yH2O: A view on the bulk Co electronic properties

Author

Leininger, Philippe, Rueff, J. -P., Mariot, J. -M., Yaresko, A., Proux, O., Hazemann, J. -L., Vanko, G., Sasaki, T., and Ishii, H.

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

The electronic properties of Co in bulk Na0.7CoO2 and the superconducting hydrated compound Na0.35CoO2 - y H2O have been investigated by x-ray absorption spectroscopy (XAS) and resonant inelastic x-ray scattering (RIXS) using hard x-rays. The XAS spectra at the Co K-edge were measured in both compounds with two different polarization directions. The changes in the XAS spectra upon hydration and their polarization dependence are well accounted for by linear muffin- tin orbital calculations in the local density approximation. The underlying electronic structure indicates the strong hybridization between the Co 3d and O 2p states in both compounds, while the electron localization is enhanced in the hydrated compound due to the increase of the Co-Co interplanar distance. The Co K pre-edge further highlights the splitting of the d band as a result of the crystal field effect and demonstrates the Co valency increase when Na0.7CoO2 is hydrated. The RIXS spectra measured at the Co K-edge show an energy loss feature around 10 eV in both compounds in fair agreement with the calculated dynamical structure factor. The RIXS feature is associated to a damped plasmon excitation., Comment: 8 pages

Published
2006
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13. Redox dynamics of subduction revealed by arsenic in serpentinite

Author

Pokrovski, G.S., primary, Sanchez-Valle, C., additional, Guillot, S., additional, Borisova, A.Y., additional, Muñoz, M., additional, Auzende, A.-L., additional, Proux, O., additional, Roux, J., additional, Hazemann, J.-L., additional, Testemale, D., additional, and Shvarov, Y.V., additional

Published
2022
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14. The ThomX ICS source

Author

Dupraz, K, Alkadi, M, Alves, M, Amoudry, L, Auguste, D, Babigeon, J, Baltazar, M, Benoit, A, Bonis, J, Bonenfant, J, Bruni, C, Cassou, K, Cayla, J, Chabaud, T, Chaikovska, I, Chance, S, Chaumat, V, Chiche, R, Cobessi, A, Cornebise, P, Dalifard, O, Delerue, N, Dorkel, R, Douillet, D, Dugal, J, El Kamchi, N, El Khaldi, M, Ergenlik, E, Favier, P, Fernandez, M, Gamelin, A, Garaut, J, Garolfi, L, Gauron, P, Gauthier, F, Gonnin, A, Grasset, D, Guerard, E, Guler, H, Haissinski, J, Herry, E, Iaquaniello, G, Jacquet, M, Jules, E, Kubytskyi, V, Langlet, M, Le Barillec, T, Ledu, J, Leguidec, D, Leluan, B, Lepercq, P, Letellier-Cohen, F, Marie, R, Marrucho, J, Martens, A, Mageur, C, Mercadier, G, Mercier, B, Mistretta, E, Monard, H, Moutardier, A, Neveu, O, Nutarelli, D, Omeich, M, Peinaud, Y, Petrilli, Y, Pichet, M, Plaige, E, Prevost, C, Rudnicky, P, Soskov, V, Taurigna-Quere, M, Trochet, S, Vallerand, C, Vitez, O, Wicek, F, Wurth, S, Zomer, F, Alexandre, P, Ben El Fekih, R, Berteaud, P, Bouvet, F, Cuoq, R, Diaz, A, Dietrich, Y, Diop, M, Pedeau, D, Dupuy, E, Marteau, F, Helder, D, Hubert, N, Veteran, J, Labat, M, Lestrade, A, Letresor, A, Lopes, R, Loulergue, A, Louvet, M, Marchand, P, El Ajjouri, M, Muller, D, Nadji, A, Nadolski, L, Nagaoka, R, Petit, S, Pollina, J, Ribeiro, F, Ros, M, Salvia, J, Bobault, S, Sebdaoui, M, Sreedharan, R, Bouanai, Y, Hazemann, J, Hodeau, J, Roy, E, Jeantet, P, Lacipiere, J, Robert, P, Horodynski, J, Bzyl, H, Chapelle, C, Biagini, M, Walter, P, Bravin, A, Del Net, W, Lahera, E, Proux, O, Elleaume, H, Cormier, E, Dupraz K., Alkadi M., Alves M., Amoudry L., Auguste D., Babigeon J. -L., Baltazar M., Benoit A., Bonis J., Bonenfant J., Bruni C., Cassou K., Cayla J. -N., Chabaud T., Chaikovska I., Chance S., Chaumat V., Chiche R., Cobessi A., Cornebise P., Dalifard O., Delerue N., Dorkel R., Douillet D., Dugal J. -P., El Kamchi N., El Khaldi M., Ergenlik E., Favier P., Fernandez M., Gamelin A., Garaut J. -F., Garolfi L., Gauron P., Gauthier F., Gonnin A., Grasset D., Guerard E., Guler H., Haissinski J., Herry E., Iaquaniello G., Jacquet M., Jules E., Kubytskyi V., Langlet M., Le Barillec T., Ledu J. -F., Leguidec D., Leluan B., Lepercq P., Letellier-Cohen F., Marie R., Marrucho J. -C., Martens A., Mageur C., Mercadier G., Mercier B., Mistretta E., Monard H., Moutardier A., Neveu O., Nutarelli D., Omeich M., Peinaud Y., Petrilli Y., Pichet M., Plaige E., Prevost C., Rudnicky P., Soskov V., Taurigna-Quere M., Trochet S., Vallerand C., Vitez O., Wicek F., Wurth S., Zomer F., Alexandre P., Ben El Fekih R., Berteaud P., Bouvet F., Cuoq R., Diaz A., Dietrich Y., Diop M., Pedeau D., Dupuy E., Marteau F., Helder D., Hubert N., Veteran J., Labat M., Lestrade A., Letresor A., Lopes R., Loulergue A., Louvet M., Marchand P., El Ajjouri M., Muller D., Nadji A., Nadolski L., Nagaoka R., Petit S., Pollina J. -P., Ribeiro F., Ros M., Salvia J., Bobault S., Sebdaoui M., Sreedharan R., Bouanai Y., Hazemann J. -L., Hodeau J. -L., Roy E., Jeantet P., Lacipiere J., Robert P., Horodynski J. -M., Bzyl H., Chapelle C., Biagini M., Walter P., Bravin A., Del Net W., Lahera E., Proux O., Elleaume H., Cormier E., Dupraz, K, Alkadi, M, Alves, M, Amoudry, L, Auguste, D, Babigeon, J, Baltazar, M, Benoit, A, Bonis, J, Bonenfant, J, Bruni, C, Cassou, K, Cayla, J, Chabaud, T, Chaikovska, I, Chance, S, Chaumat, V, Chiche, R, Cobessi, A, Cornebise, P, Dalifard, O, Delerue, N, Dorkel, R, Douillet, D, Dugal, J, El Kamchi, N, El Khaldi, M, Ergenlik, E, Favier, P, Fernandez, M, Gamelin, A, Garaut, J, Garolfi, L, Gauron, P, Gauthier, F, Gonnin, A, Grasset, D, Guerard, E, Guler, H, Haissinski, J, Herry, E, Iaquaniello, G, Jacquet, M, Jules, E, Kubytskyi, V, Langlet, M, Le Barillec, T, Ledu, J, Leguidec, D, Leluan, B, Lepercq, P, Letellier-Cohen, F, Marie, R, Marrucho, J, Martens, A, Mageur, C, Mercadier, G, Mercier, B, Mistretta, E, Monard, H, Moutardier, A, Neveu, O, Nutarelli, D, Omeich, M, Peinaud, Y, Petrilli, Y, Pichet, M, Plaige, E, Prevost, C, Rudnicky, P, Soskov, V, Taurigna-Quere, M, Trochet, S, Vallerand, C, Vitez, O, Wicek, F, Wurth, S, Zomer, F, Alexandre, P, Ben El Fekih, R, Berteaud, P, Bouvet, F, Cuoq, R, Diaz, A, Dietrich, Y, Diop, M, Pedeau, D, Dupuy, E, Marteau, F, Helder, D, Hubert, N, Veteran, J, Labat, M, Lestrade, A, Letresor, A, Lopes, R, Loulergue, A, Louvet, M, Marchand, P, El Ajjouri, M, Muller, D, Nadji, A, Nadolski, L, Nagaoka, R, Petit, S, Pollina, J, Ribeiro, F, Ros, M, Salvia, J, Bobault, S, Sebdaoui, M, Sreedharan, R, Bouanai, Y, Hazemann, J, Hodeau, J, Roy, E, Jeantet, P, Lacipiere, J, Robert, P, Horodynski, J, Bzyl, H, Chapelle, C, Biagini, M, Walter, P, Bravin, A, Del Net, W, Lahera, E, Proux, O, Elleaume, H, Cormier, E, Dupraz K., Alkadi M., Alves M., Amoudry L., Auguste D., Babigeon J. -L., Baltazar M., Benoit A., Bonis J., Bonenfant J., Bruni C., Cassou K., Cayla J. -N., Chabaud T., Chaikovska I., Chance S., Chaumat V., Chiche R., Cobessi A., Cornebise P., Dalifard O., Delerue N., Dorkel R., Douillet D., Dugal J. -P., El Kamchi N., El Khaldi M., Ergenlik E., Favier P., Fernandez M., Gamelin A., Garaut J. -F., Garolfi L., Gauron P., Gauthier F., Gonnin A., Grasset D., Guerard E., Guler H., Haissinski J., Herry E., Iaquaniello G., Jacquet M., Jules E., Kubytskyi V., Langlet M., Le Barillec T., Ledu J. -F., Leguidec D., Leluan B., Lepercq P., Letellier-Cohen F., Marie R., Marrucho J. -C., Martens A., Mageur C., Mercadier G., Mercier B., Mistretta E., Monard H., Moutardier A., Neveu O., Nutarelli D., Omeich M., Peinaud Y., Petrilli Y., Pichet M., Plaige E., Prevost C., Rudnicky P., Soskov V., Taurigna-Quere M., Trochet S., Vallerand C., Vitez O., Wicek F., Wurth S., Zomer F., Alexandre P., Ben El Fekih R., Berteaud P., Bouvet F., Cuoq R., Diaz A., Dietrich Y., Diop M., Pedeau D., Dupuy E., Marteau F., Helder D., Hubert N., Veteran J., Labat M., Lestrade A., Letresor A., Lopes R., Loulergue A., Louvet M., Marchand P., El Ajjouri M., Muller D., Nadji A., Nadolski L., Nagaoka R., Petit S., Pollina J. -P., Ribeiro F., Ros M., Salvia J., Bobault S., Sebdaoui M., Sreedharan R., Bouanai Y., Hazemann J. -L., Hodeau J. -L., Roy E., Jeantet P., Lacipiere J., Robert P., Horodynski J. -M., Bzyl H., Chapelle C., Biagini M., Walter P., Bravin A., Del Net W., Lahera E., Proux O., Elleaume H., and Cormier E.

Abstract

ThomX is a new generation Compact Compton Source. It is currently commissioned by and at the IJCLab (Laboratoire de physique des 2 infinis - Irène Joliot-Curie (UMR9012)) at Orsay. The first beam is expected at the begining of 2021. The aim of ThomX is to demonstrate the characteristics of an intense and Compact (lab-size) X-ray source based on Compton Scattering. The performances are mostly driven by the laser optical system which is above the state of the art of stored laser power. Proof of principle of various X-ray techniques will be performed thanks to the versatile ThomX beamline. Firstly, this article presents the machine description. Secondly, the issues and limits of the laser system are discussed. Then, the ThomX beamline is described and the machine status conclude the ThomX presentation. Finally, the expected performances for the next years and the possible experiments that can be made with this new machine are detailed.

Published
2020

16. Metal ion binding in wild-type and mutated frataxin: a stability study

Author

Morante, S, Botticelli, S, Chiaraluce, R, Consalvi, V, La Penna, G, Novak, L, Pasquo, A, Petrosino, M, Proux, O, Rossi, G, Salina, G, and Stellato, F

Subjects
frataxin, metal ions, Co2+, frataxin mutants, XAS (XAFS, XANES), thermal stability, XANES), Settore FIS/07, Biochemistry, Genetics and Molecular Biology (miscellaneous), Biochemistry, metal ions (Co2+), termal stability, Molecular Biology, XAS (XAFS
Abstract

This work studies the stability of wild-type frataxin and some of its variants found in cancer tissues upon Co2+ binding. Although the physiologically involved metal ion in the frataxin enzymatic activity is Fe2+, as it is customarily done, Co2+ is most often used in experiments because Fe2+ is extremely unstable owing to the fast oxidation reaction Fe2+ → Fe3+. Protein stability is monitored following the conformational changes induced by Co2+ binding as measured by circular dichroism, fluorescence spectroscopy, and melting temperature measurements. The stability ranking among the wild-type frataxin and its variants obtained in this way is confirmed by a detailed comparative analysis of the XAS spectra of the metal-protein complex at the Co K-edge. In particular, a fit to the EXAFS region of the spectrum allows positively identifying the frataxin acidic ridge as the most likely location of the metal-binding sites. Furthermore, we can explain the surprising feature emerging from a detailed analysis of the XANES region of the spectrum, showing that the longer 81-210 frataxin fragment has a smaller propensity for Co2+ binding than the shorter 90-210 one. This fact is explained by the peculiar role of the N-terminal disordered tail in modulating the protein ability to interact with the metal.

Published
2022

19. An arsenic-driven pump for invisible gold in hydrothermal systems

Author

Pokrovski, G.S., primary, Escoda, C., additional, Blanchard, M., additional, Testemale, D., additional, Hazemann, J.-L., additional, Gouy, S., additional, Kokh, M.A., additional, Boiron, M.-C., additional, de Parseval, F., additional, Aigouy, T., additional, Menjot, L., additional, de Parseval, P., additional, Proux, O., additional, Rovezzi, M., additional, Béziat, D., additional, Salvi, S., additional, Kouzmanov, K., additional, Bartsch, T., additional, Pöttgen, R., additional, and Doert, T., additional

Published
2021
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20. X-ray imaging and X-Ray Absorption Spectroscopy applied to Environmental Nanotechnologies

Author

Melanie Auffan, Jerome ROSE, Proux, O., Kieffer, I., J-L, Hazemann, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), and Auffan, Melanie

Subjects
[SDE] Environmental Sciences, [SDE]Environmental Sciences, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2020

26. Operando X-ray Absorption Spectroscopy Investigation of Photocatalytic Hydrogen Evolution over Ultradispersed Pt/TiO2 Catalysts

Author

Piccolo, L., primary, Afanasiev, P., additional, Morfin, F., additional, Len, T., additional, Dessal, C., additional, Rousset, J. L., additional, Aouine, M., additional, Bourgain, F., additional, Aguilar-Tapia, A., additional, Proux, O., additional, Chen, Y., additional, Soler, L., additional, and Llorca, J., additional

Published
2020
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28. High-Energy Resolution Fluorescence Detected X-Ray Absorption Spectroscopy: A Powerful Structural Tool in Environmental Nanotechnologies

Author

Auffan, Melanie, Rose, J, Proux, O, Kieffer, I, Hazemann, J-L, Auffan, Melanie, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), and Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDE] Environmental Sciences, [SDE]Environmental Sciences
Abstract

International audience; Engineered nanomaterials (ENMs) have become a fast growing economic sector. As a consequence of the many debates concerning their safety, efforts are developed at international and national levels to develop a code of ethics for a safe and responsible development of ENMs. A sustained growth of the nanotechnology industry will rely heavily on the characterization of risks to the environment (water and soil resources, trophic transfers, biodiversity) and human health that may be posed by ENMs.In this regard, physical-chemists, (micro)biologists, and ecologists need to conduct meaningful experiments to study the environmental risk of engineered nanomaterials with access torelevant mechanistic data across several spatial and temporal scales (Auffan et al. 2019). Experimental devices as mesocosms that can be tailored to virtually mimic any ecosystemappear as a particularly well-suited device (Auffan et al. 2014). Mesocosm testing bears clear advantages for the determination of both exposure ((bio)distribution, (bio)transformation) and hazard (sub-individual, individual, and community levels) following relevant exposure scenarios (low doses, mid-long term exposure), and for producing dependable andintercomparable data. Adhering to environmentally relevant exposure scenarios implicitly represents a technical challenge since it requires to explore the speciation of a target chemical element at natural concentration levels in complex matrices, which is critical in the fields of environmental and biogeochemistry sciences. The sharp and well-marked features of the HERFD–X-ray absorption near-edge structure spectra enabled us to determine unambiguously and with greater precision the speciation of the probed metal composing ENMs. This was a major technological advance, with strong benefits for the study of the behavior, and fate of highly diluted elements using XAS. We then illustrate the positive impact of this technique in terms of detection limit with two examples dealing with Ce- and Ag-based ENMs in ecologically relevant organisms (Tella et al. 2014, 2015).1) Auffan M, Masion A, Mouneyrac C, de Garidel-Thoron C, Hendren CO, Thiery A, Santaella C, Giamberini L, Bottero J-Y, Wiesner MR, Rose J NanoImpact 2019 13: 66-69.2) Auffan M, Tella M, Santaella C, Brousset L, Pailles C, Barakat M, Espinasse B, Artells E, Issartel J, Masion A, Rose J, Wiesner M, Achouak W, Thiery A, Bottero J-Y Scientific reports 2014 4: 5608.3) Tella M, Auffan M, Brousset L, Issartel J, Kieffer I, Pailles C, Morel E, Santaella C, Angeletti B, Artells E, Rose J, Thiery A, Bottero J-Y Environmental Science & Technology 2014 48: 9004–9013.4) Tella M, Auffan M, Brousset L, Morel E, Proux O, Chaneac C, Angeletti B, Pailles C, Artells E, Santaella C, Rose J, Thiery A, Bottero J-Y Environmental Science: Nano 2015 2: 653-663.

Published
2019

31. Electronic structure of self-doped layered Eu3F4Bi2S4 material revealed by x-ray absorption spectroscopy and photoelectron spectromicroscopy

Author

Sugimoto, T., Wakita, T., Barinov, A., Terashima, K., Kandyba, Viktor, Proux, O., Kajitani, J., Higashinaka, R., Matsuda, T. D., Aoki, Y., Yokoya, T., Mizokawa, T., Saini, N. L., Paris, E., Sugimoto, T., Wakita, T., Barinov, A., Terashima, K., Kandyba, Viktor, Proux, O., Kajitani, J., Higashinaka, R., Matsuda, T. D., Aoki, Y., Yokoya, T., Mizokawa, T., Saini, N. L., and Paris, E.

Subjects
Electronic, optical and magnetic materials, Condensed Matter Physics, band structure, microscale phase separation, layered structures, Eu3F4Bi2S4, x-ray absorption spectroscopy, angle-resolved photoemission spectroscopy, superconductors, superconductor, layered structure
Abstract

We have studied the electronic structure of Eu3F4Bi2S4 using a combination of Eu L3-edge x-ray absorption spectroscopy (XAS) and space-resolved angle-resolved photoemission spectroscopy (ARPES). From the Eu L3-edge XAS, we have found that the Eu in this system is in mixed valence state with coexistence of Eu2+/Eu3+. The bulk charge doping was estimated to be ∼0.3 per Bi site in Eu3F4Bi2S4, which corresponds to the nominal x in a typical REO1−xFxBiS2 system (RE: rare-earth elements). From the space-resolved ARPES, we have ruled out the possibility of any microscale phase separation of Eu valence in the system. Using a microfocused beam we have observed the band structure as well as the Fermi surface that appeared similar to other compounds of this family with disconnected rectangular electronlike pockets around the X point. The Luttinger volume analysis gives the effective carrier to be 0.23 electrons per Bi site in Eu3F4Bi2S4, indicating that the system is likely to be in the underdoped region of its superconducting phase diagram.

Published
2017

33. Oxide phase characterization in simulated high burn-up UO$_2$ fuels in the early stages of a nuclear severe accident

Author

Le Gall, C., Geiger, E., Proux, O., Rovezzi, M., Solari, P. L., Hunault, M., Klosek, V., Riglet Martial, C., Léchelle, J., Audubert, F., Yves Pontillon, L Hazemann, J., Colomp, P., CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), European Synchrotron Radiation Facility (ESRF), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), CADARACHE, Bibliothèque, Matériaux, Rayonnements, Structure (NEEL - MRS), Institut Néel (NEEL), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and European Synchroton Radiation Facility [Grenoble] (ESRF)

Subjects
[PHYS.NUCL] Physics [physics]/Nuclear Theory [nucl-th], [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2018

37. Geochemical control on the reduction of U(VI) to mononuclear U(IV) species in lacustrine sediments

Author

CMM Groep Klumperman, CMM Sectie Celbiologie, Cancer, Hubrecht Institute with UMC, Stetten, L., Mangeret, A., Brest, J., Seder-Colomina, M., Le Pape, P., Ikogou, M., Zeyen, N., Thouvenot, A., Julien, A., Alcalde, G., Reyss, J. L., Bombled, B., Rabouille, C., Olivi, L., Proux, O., Cazala, C., Morin, G., CMM Groep Klumperman, CMM Sectie Celbiologie, Cancer, Hubrecht Institute with UMC, Stetten, L., Mangeret, A., Brest, J., Seder-Colomina, M., Le Pape, P., Ikogou, M., Zeyen, N., Thouvenot, A., Julien, A., Alcalde, G., Reyss, J. L., Bombled, B., Rabouille, C., Olivi, L., Proux, O., Cazala, C., and Morin, G.

Published
2018

38. An innovative Method to study Volatile Fission Products speciation in nuclear fuels under Severe Accident Conditions

Author

Hein, H., Hazemann, Jl., Proux, O., Riglet-Martial, C., Léchelle, J., Audubert, F., Pontillon, Yves, Le Gall, C., Cologna, M., Holzhauser, M., Popa, K., Boshoven, J., European Commission - Joint Research Centre [Seville] (JRC), European Synchroton Radiation Facility [Grenoble] (ESRF), European Synchrotron Radiation Facility (ESRF), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), ESRF- The European Synchrotron Radiation Facility, Grenoble, and amplexor, amplexor

Subjects
[PHYS.NUCL] Physics [physics]/Nuclear Theory [nucl-th], in-situ XAS, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], Cesium, SPS, Fission products, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Severe accident, volatile
Abstract

International audience; The development of realistic models for fission products behavior during a severe accident requires experimental data on fission products speciation into the fuel (as irradiated and during the transient) together with thermodynamic predictions. Due to the limitations in terms of experiments and characterization techniques available to study fission products speciation in nuclear irradiated fuels, simulant materials (SIMFUEL manufactured thanks to conventional process) are often used. However, these materials do not allow the study of volatile fission products because they are totally released during the sintering stage. In the case of SIMFUEL with implanted fission products surrogates, the chemical state and the corresponding evolution of the phases during the thermal sequence are not entirely representative of the real case. An innovative method to study volatile fission products speciation in SIMFUEL samples has thus been developed. Spark plasma sintering was used to synthesize dense SIMFUEL samples containing cesium in collaboration with the JRC-Karlsruhe within the frame of the GENTLE program. Thermodynamic calculations made using the TAF-ID v.6 associated with the FACTSage software enabled to determine the conditions in which to perform thermal treatments. In-temperature XAS experiments in conditions representative of a sevre accident are developed in collaboration with FAME-UHD beamline at the ESRF (Grenoble, France). Additional thermal treatments will also be performed to enable further characterizations (ceramography, SEM-EDX...).

Published
2017

40. Competition between CoOx and CoPt phases in Pt/Co/AlOx semi tunnel junctions.

Author

Garad, H., Ortega, L., Ramos, A. Y., Joly, Y., Fettar, F., Auffret, S., Rodmacq, B., Diény, B., Proux, O., and Erko, A. I.

Subjects
TUNNEL junctions (Materials science), COBALT oxides, COBALT platinum films, ANNEALING of metals, OXIDATION
Abstract

We report on the evolution of the structure and composition of a Pt(3 nm)/Co(0.6 nm)/AlOx(2 nm) trilayer sputtered on Si/SiO2 under oxidation and annealing processes by combined x-ray reflectivity and x-ray absorption studies. We describe the progressive and inhomogeneous oxidation of the layers by increasing the oxidation time. Before annealing, the layers have lower density than bulk samples and noticeable roughness. After thermal annealing, a significant improvement of the quality of the alumina layer goes along with the formation of a CoPt alloy that reduces the number of Co-O bonds. These structural outcomes clarify the evolution of the magnetic and transport properties reported at room temperature in these samples. [ABSTRACT FROM AUTHOR]

Published
2013
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44. Distinct local structure of superconducting Ca10M4As8(Fe2As2)5(M=Pt,Ir)

Author

Paris, E., primary, Wakita, T., additional, Proux, O., additional, Yokoya, T., additional, Kudo, K., additional, Mitsuoka, D., additional, Kimura, T., additional, Fujimura, K., additional, Nishimoto, N., additional, Ioka, S., additional, Nohara, M., additional, Mizokawa, T., additional, and Saini, N. L., additional

Published
2017
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46. Effect of field site hydrogeochemical conditions on the corrosion of milled zerovalent iron particles and their dechlorination efficiency

Author

Velimirovic, M., Auffan, M., Carniato, L., Micić Batka, V., Schmid, D., Wagner, Stephan, Borschneck, D., Proux, O., von der Kammer, F., Hofmann, T., Velimirovic, M., Auffan, M., Carniato, L., Micić Batka, V., Schmid, D., Wagner, Stephan, Borschneck, D., Proux, O., von der Kammer, F., and Hofmann, T.

Abstract

Milled zerovalent iron (milled ZVI) particles have been recognized as a promising agent for groundwater remediation because of (1) their high reactivity with chlorinated aliphatic hydrocarbons, organochlorine pesticides, organic dyes, and a number of inorganic contaminants, and (2) a possible greater persistance than the more extensively investigated nanoscale zerovalent iron. We have used laboratory-scale batch degradation experiments to investigate the effect that hydrogeochemical conditions have on the corrosion of milled ZVI and on its ability to degrade trichloroethene (TCE). The observed pseudo first-order degradation rate constants indicated that the degradation of TCE by milled ZVI is affected by groundwater chemistry. The apparent corrosion rates of milled ZVI particles were of the same order of magnitude for hydrogeochemical conditions representative for two contaminated field sites (133–140 mmol kg− 1 day− 1, indicating a milled ZVI life-time of 128–135 days). Sulfate enhances milled ZVI reactivity by removing passivating iron oxides and hydroxides from the Fe0 surface, thus increasing the number of reactive sites available. The organic matter content of 1.69% in the aquifer material tends to suppress the formation of iron corrosion precipitates. Results from scanning electron microscopy, X-ray diffraction, and iron K-edge X-ray adsorption spectroscopy suggest that the corrosion mechanisms involve the partial dissolution of particles followed by the formation and surface precipitation of magnetite and/or maghemite. Numerical corrosion modeling revealed that fitting iron corrosion rates and hydrogen inhibitory terms to hydrogen and pH measurements in batch reactors can reduce the life-time of milled ZVI particles by a factor of 1.2 to 1.7.

Published
2017

47. Potentiel d’une source Compton pour les applications en science des matériaux ; exemple de ThomX

Author

Jean-Louis Hodeau, Jean-Louis Hazemann, Pauline Martinetto, Marie Jacquet, Philippe Walter, Alberto Bravin, François Estève, Proux, O., Nathalie Boudet, Philippe Jeantet, Lacipiere, J., Emmanuel Roy, Cyril Bruyère, Alessandro Variola, Matériaux, Rayonnements, Structure (MRS), Institut Néel (NEEL), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire de l'Accélérateur Linéaire (LAL), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Centre de recherche et de restauration des musées de France (C2RMF), Centre National de la Recherche Scientifique (CNRS)-Ministère de la Culture et de la Communication (MCC), European Synchrotron Radiation Facility (ESRF), Rayonnement Synchrotron et Recherche Medicale (RSRM), Université Joseph Fourier - Grenoble 1 (UJF)-European Synchrotron Radiation Facility (ESRF)-Institut National de la Santé et de la Recherche Médicale (INSERM), Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), CRG et Grands Instruments (CRG ), SERAS (SERAS ), Association Française de Cristallographie, ANR-10-EQPX-0051,ThomX,Source X monochromatique compacte(2010), MRS - Matériaux, Rayonnements, Structure, Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), CRG - CRG et Grands Instruments, SERAS - SERAS, and ANR-10-EQPX-0051/10-EQPX-0051,ThomX,Source X monochromatique compacte(2010)

Subjects
[CHIM.CRIS]Chemical Sciences/Cristallography, [CHIM.MATE]Chemical Sciences/Material chemistry, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2016

49. Electronic structure of self-doped layeredEu3F4Bi2S4material revealed by x-ray absorption spectroscopy and photoelectron spectromicroscopy

Author

Paris, E., primary, Sugimoto, T., additional, Wakita, T., additional, Barinov, A., additional, Terashima, K., additional, Kandyba, V., additional, Proux, O., additional, Kajitani, J., additional, Higashinaka, R., additional, Matsuda, T. D., additional, Aoki, Y., additional, Yokoya, T., additional, Mizokawa, T., additional, and Saini, N. L., additional

Published
2017
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