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Parchenko S, Frej A, Ueda H, Carley R, Mercadier L, Gerasimova N, Mercurio G, Schlappa J, Yaroslavtsev A, Agarwal N, Gort R, Scherz A, Zvezdin A, Stupakiewicz A, Staub U. Transient Non-Collinear Magnetic State for All-Optical Magnetization Switching. Adv Sci (Weinh) 2023; 10:e2302550. [PMID: 37939279 PMCID: PMC10754071 DOI: 10.1002/advs.202302550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 09/19/2023] [Indexed: 11/10/2023]
Abstract
Resonant absorption of a photon by bound electrons in a solid can promote an electron to another orbital state or transfer it to a neighboring atomic site. Such a transition in a magnetically ordered material could affect the magnetic order. While this process is an obvious road map for optical control of magnetization, experimental demonstration of such a process remains challenging. Exciting a significant fraction of magnetic ions requires a very intense incoming light beam, as orbital resonances are often weak compared to above-band-gap excitations. In the latter case, a sizeable reduction of the magnetization occurs as the absorbed energy increases the spin temperature, masking the non-thermal optical effects. Here, using ultrafast X-ray spectroscopy, this work is able to resolve changes in the magnetization state induced by resonant absorption of infrared photons in Co-doped yttrium iron garnet, with negligible thermal effects. This work finds that the optical excitation of the Co ions affects the two distinct magnetic Fe sublattices differently, resulting in a transient non-collinear magnetic state. The present results indicate that the all-optical magnetization switching (AOS) most likely occurs due to the creation of a transient, non-collinear magnetic state followed by coherent spin rotations of the Fe moments.
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Affiliation(s)
- Sergii Parchenko
- Laboratory for Mesoscopic SystemsDepartment of MaterialsETH ZurichZurich8093Switzerland
- Laboratory for Multiscale Materials ExperimentsPaul Scherrer InstituteVilligen PSI5232Switzerland
- European XFELHolzkoppel 422869SchenefeldGermany
| | - Antoni Frej
- Faculty of PhysicsUniversity of Bialystok1L CiolkowskiegoBialystok15‐245Poland
| | - Hiroki Ueda
- Swiss Light SourcePaul Scherrer InstituteVilligen5232Switzerland
- SwissFELPaul Scherrer InstitutVilligen5232Switzerland
| | | | | | | | | | | | | | - Naman Agarwal
- European XFELHolzkoppel 422869SchenefeldGermany
- Department of Physics and AstronomyAarhus UniversityAarhus8000Denmark
| | - Rafael Gort
- European XFELHolzkoppel 422869SchenefeldGermany
| | | | - Anatoly Zvezdin
- Prokhorov General Physics Institute of the Russian Academy of SciencesVavilova 38Moscow119991Russia
- Russia – New Spintronic TechnologiesBolshoy Bulvar 30, bld. 1Moscow121205Russia
| | | | - Urs Staub
- Swiss Light SourcePaul Scherrer InstituteVilligen5232Switzerland
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2
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Fleming C, Vu S, Brook DJR, Agrestini S, Pellegrin E, DaRos J. Metal-ligand interactions in a redox active ligand system. Electrochemistry and spectroscopy of [M(dipyvd) 2] n+ (M=Zn, Ni, n=0, 1, 2). Front Chem 2023; 11:1295289. [PMID: 38033468 PMCID: PMC10684738 DOI: 10.3389/fchem.2023.1295289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 10/27/2023] [Indexed: 12/02/2023] Open
Abstract
Reaction of nickel and zinc triflates with the tridentate leucoverdazyl 1-isopropyl-3,5-di (2'-pyridyl)-6-oxo-2H-tetrazine (dipyvdH) and triethylamine resulted in the neutral coordination compounds M(dipyvd)2 (M = Ni,Zn). In acetonitrile, both compounds undergo two one electron oxidation processes, Zn (dipyvd)2 at -0.28 V and -0.12 V and Ni(dipyvd)2 at -0.32 V and -0.15 V vs ferrocene/ferricenium. Oxidations are ligand based resulting in an intermediate mixed valence species and a cationic bis(verdazyl) compound respectively. Oxidation of the ligand changes a localized, antiaromatic, non-planar 8π electron anion to a planar, delocalized 7π electron radical. The change in ligand structure results in an increase in the octahedral ligand field splitting from 10,500 cm-1 to ∼13,000 cm-1, suggesting an increase in the pi acceptor character of the ligand. In the mixed valence species, spectroscopic data suggests minimal interaction between ligands mediated by the metal center; i.e., these are class I-II systems in the Robin-Day classification.
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Affiliation(s)
- Connor Fleming
- Department of Chemistry, San Jose State University, San Jose, CA, United States
| | - Son Vu
- Department of Chemistry, San Jose State University, San Jose, CA, United States
| | - David J. R. Brook
- Department of Chemistry, San Jose State University, San Jose, CA, United States
| | - Stefano Agrestini
- ALBA Synchrotron Light Source, E-08290 Cerdanyola del Vallès, Barcelona, Spain
| | - Eric Pellegrin
- ALBA Synchrotron Light Source, E-08290 Cerdanyola del Vallès, Barcelona, Spain
| | - Jeffrey DaRos
- Department of Chemistry, San Jose State University, San Jose, CA, United States
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3
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Gee LB, Lim J, Kroll T, Sokaras D, Alonso-Mori R, Lee CM. Unraveling Metal-Ligand Bonding in an HNO-Evolving {FeNO} 6 Complex with a Combined X-ray Spectroscopic Approach. J Am Chem Soc 2023; 145:20733-20738. [PMID: 37610249 PMCID: PMC10876219 DOI: 10.1021/jacs.3c04479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Photolytic delivery of nitric oxide and nitroxide has substantial biomedical and phototherapeutic applications. Here, we utilized hard X-ray spectroscopic methods to identify key geometric and electronic structural features of two photolabile {FeNO}6 complexes where the compounds differ in the presence of a pendant thiol in [Fe(NO)(TMSPS2)(TMSPS2H)] and thioether in [Fe(NO)(TMSPS2)(TMSPS2CH3)] with the former complex being the only transition metal system to photolytically generate HNO. Fe Kβ XES identifies the photoreactant systems as essentially Fe(II)-NO+, while valence-to-core XES extracts a NO oxidation state of +0.5. Finally, the pre-edge of the Fe high-energy-resolution fluorescence detected (HERFD) XAS spectra is shown to be acutely sensitive to perturbation of the Fe-NO covalency enhanced by the 3d-4p orbital mixing dipole intensity contribution. Collectively, this X-ray spectroscopic approach enables future time-resolved insights in these systems and extensions to other challenging redox noninnocent {FeNO}x systems.
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Affiliation(s)
- Leland B. Gee
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Jinkyu Lim
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
- SSRL, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Thomas Kroll
- SSRL, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Dimosthenis Sokaras
- SSRL, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Roberto Alonso-Mori
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Chien-Ming Lee
- Department of Applied Science, National Taitung University, Taitung 950, Taiwan
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Ferron T, Fiori ME, Ediger MD, DeLongchamp DM, Sunday DF. Composition Dictates Molecular Orientation at the Heterointerfaces of Vapor-Deposited Glasses. JACS Au 2023; 3:1931-1938. [PMID: 37502150 PMCID: PMC10369407 DOI: 10.1021/jacsau.3c00168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/22/2023] [Accepted: 06/09/2023] [Indexed: 07/29/2023]
Abstract
Physical vapor deposition (PVD) can prepare organic glasses with a preferred molecular orientation. The relationships between deposition conditions and orientation have been extensively investigated in the film bulk. The role of interfaces on the structure is less well understood and remains a key knowledge gap, as the interfacial region can govern glass stability and optoelectronic properties. Robust experimental characterization has remained elusive due to complexities in interrogating molecular organization in amorphous, organic materials. Polarized soft X-rays are sensitive to both the composition and the orientation of transition dipole moments in the film, making them uniquely suited to probe molecular orientation in amorphous soft matter. Here, we utilize polarized resonant soft X-ray reflectivity (P-RSoXR) to simultaneously depth profile the composition and molecular orientation of a bilayer prepared through the physical vapor deposition of 1,4-di-[4-(N,N-diphenyl)amino]styryl-benzene (DSA-Ph) on a film of aluminum-tris(8-hydroxyquinoline) (Alq3). The bulk orientation of the DSA-Ph layer is controlled by varying deposition conditions. Utilizing P-RSoXR to depth profile the films enables determination of both the bulk orientation of DSA-Ph and the orientation near the Alq3 interface. At the Alq3 surface, DSA-Ph always lies with its long axis parallel to the interface, before transitioning into the bulk orientation. This is likely due to the lower mobility and higher glass transition of Alq3, as the first several monolayers of DSA-Ph deposited on Alq3 appear to behave as a blend. We further show how orientation at the interface correlates with the bulk behavior of a codeposited glass of similar blend composition, demonstrating a straightforward approach to predicting molecular orientation at heterointerfaces. This work provides key insights into how molecules orient during vapor deposition and offers methods to predict this property, a critical step toward controlling interfacial behavior in soft matter.
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Affiliation(s)
- Thomas
J. Ferron
- National
Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Marie E. Fiori
- Department
of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - M. D. Ediger
- Department
of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Dean M. DeLongchamp
- National
Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Daniel F. Sunday
- National
Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
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Petit T, Lounasvuori M, Chemin A, Bärmann P. Nanointerfaces: Concepts and Strategies for Optical and X-ray Spectroscopic Characterization. ACS Phys Chem Au 2023; 3:263-278. [PMID: 37249937 PMCID: PMC10214513 DOI: 10.1021/acsphyschemau.2c00058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 01/25/2023] [Accepted: 01/25/2023] [Indexed: 05/31/2023]
Abstract
Interfaces at the nanoscale, also called nanointerfaces, play a fundamental role in physics and chemistry. Probing the chemical and electronic environment at nanointerfaces is essential in order to elucidate chemical processes relevant for applications in a variety of fields. Many spectroscopic techniques have been applied for this purpose, although some approaches are more appropriate than others depending on the type of the nanointerface and the physical properties of the different phases. In this Perspective, we introduce the major concepts to be considered when characterizing nanointerfaces. In particular, the interplay between the characteristic length of the nanointerfaces, and the probing and information depths of different spectroscopy techniques is discussed. Differences between nano- and bulk interfaces are explained and illustrated with chosen examples from optical and X-ray spectroscopies, focusing on solid-liquid nanointerfaces. We hope that this Perspective will help to prepare spectroscopic characterization of nanointerfaces and stimulate interest in the development of new spectroscopic techniques adapted to the nanointerfaces.
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McGuire SC, Zhang Y, Wong SS. A combined TEM and SAXS study of the growth and self-assembly of ultrathin Pt nanowires. Nanotechnology 2022; 33:475602. [PMID: 36044706 DOI: 10.1088/1361-6528/ac893b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 08/11/2022] [Indexed: 06/15/2023]
Abstract
Ultrathin Pt nanowires possess high activity for various electrocatalytic applications. However, little work has focused on understanding their growth mechanisms. Herein, we utilize a combination of time-dependent,ex situtransmission electron microscopy (TEM) and small angle x-ray scattering (SAXS) techniques to observe the growth process in addition to associated surfactant-based interactions. TEM images indicate that initially nanoparticles are formed within 30 s; these small 'seed' particles quickly elongate to form ultrathin nanowires after 2 min. These motifs remain relatively unchanged in size and shape up to 480 min of reaction. Complementary SAXS data suggests that the initial nanoparticles, which are coated by a surfactant bilayer, arrange into abccsuperlattice. With increasing reaction time, thebcclattice disappears as the nanoparticles grow into nanowires, which then self-assemble into a columnar hexagonal structure in which the individual nanowires are covered by a CTAB monolayer. The hexagonal structure eventually degrades, thereby leading to the formation of lamellar stacking phases comprised of surfactant bilayers. To the best of our knowledge, this is the first time that SAXS has been used to monitor the growth and self-assembly of Pt nanowires. These insights can be used to better understand and rationally control the formation of anisotropic motifs of other metallic nanostructures.
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Affiliation(s)
- Scott C McGuire
- Department of Chemistry, State University of New York at Stony Brook, Stony Brook, NY 11794-3400, United States of America
| | - Yugang Zhang
- Center for Functional Nanomaterials, Building 735, Brookhaven National Laboratory, Upton, NY 11973, United States of America
| | - Stanislaus S Wong
- Department of Chemistry, State University of New York at Stony Brook, Stony Brook, NY 11794-3400, United States of America
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Frontini F, Lebert BW, Cho KK, Song MS, Cho BK, Pollock CJ, Kim YJ. Intermediate valence state in YbB 4revealed by resonant x-ray emission spectroscopy. J Phys Condens Matter 2022; 34:345601. [PMID: 35667370 DOI: 10.1088/1361-648x/ac7629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 06/06/2022] [Indexed: 06/15/2023]
Abstract
We report the temperature dependence of the Yb valence in the geometrically frustrated compoundYbB4from 12 to 300 K using resonant x-ray emission spectroscopy at the YbLα1transition. We find that the Yb valence,v, is hybridized between thev = 2 andv = 3 valence states, increasing fromv=2.61±0.01at 12 K tov=2.67±0.01at 300 K, confirming thatYbB4is a Kondo system in the intermediate valence regime. This result indicates that the Kondo interaction inYbB4is substantial, and is likely to be the reason whyYbB4does not order magnetically at low temperature, rather than this being an effect of geometric frustration. Furthermore, the zero-point valence of the system is extracted from our data and compared with other Kondo lattice systems. The zero-point valence seems to be weakly dependent on the Kondo temperature scale, but not on the valence change temperature scaleTv.
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Affiliation(s)
- Felix Frontini
- Department of Physics, University of Toronto, 60 St. George Street, Toronto, ON M5S 1A7, Canada
| | - Blair W Lebert
- Department of Physics, University of Toronto, 60 St. George Street, Toronto, ON M5S 1A7, Canada
| | - K K Cho
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology, 61005 Gwangju, Republic of Korea
| | - M S Song
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology, 61005 Gwangju, Republic of Korea
| | - B K Cho
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology, 61005 Gwangju, Republic of Korea
| | - Christopher J Pollock
- Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853, United States of America
| | - Young-June Kim
- Department of Physics, University of Toronto, 60 St. George Street, Toronto, ON M5S 1A7, Canada
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Szabo CI, Cline JP, Henins A, Hudson LT, Mendenhall MH. The NIST Vacuum Double-Crystal Spectrometer: A Tool for SI-Traceable Measurement of X-Ray Emission Spectra. J Res Natl Inst Stand Technol 2022; 126:126049. [PMID: 38469442 PMCID: PMC10046760 DOI: 10.6028/jres.126.049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 12/11/2021] [Indexed: 03/13/2024]
Abstract
The NIST Vacuum Double-Crystal Spectrometer (VDCS) has been modernized and is now capable of recording reference-free wavelength-dispersive spectra in the 2 keV to 12 keV x-ray energy range. The VDCS employs crystals in which the lattice spacings are traceable to the definition of the meter through x-ray optical interferometry with a relative uncertainty ﹤10-⁸. VDCS wavelength determination relies upon precision angle difference measurements for which the encoders of the rotation stages have been calibrated using the circle closure method for accurate, absolute angle measurement. The new vacuum-compatible area detector allows quantification of the aberration functions contributing to the observed line shape and in situ alignment of the crystal optics. This latter procedure is augmented with the use of a thin lamella as the first crystal. With these new techniques, x-ray spectra are registered with the VDCS on an absolute energy scale with a relative uncertainty of 10-⁶.
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Affiliation(s)
- Csilla I. Szabo
- National Institute of Standards and Technology,
Gaithersburg, MD 20899,
USA
- Theiss Research,
La Jolla, CA 92037,
USA
| | - James P. Cline
- National Institute of Standards and Technology,
Gaithersburg, MD 20899,
USA
| | - Albert Henins
- National Institute of Standards and Technology,
Gaithersburg, MD 20899,
USA
| | - Lawrence T. Hudson
- National Institute of Standards and Technology,
Gaithersburg, MD 20899,
USA
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Leppänen E, Aarva A, Sainio S, Caro MA, Laurila T. Connection between the physicochemical characteristics of amorphous carbon thin films and their electrochemical properties. J Phys Condens Matter 2021; 33:434002. [PMID: 34343980 DOI: 10.1088/1361-648x/ac1a2e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 08/03/2021] [Indexed: 06/13/2023]
Abstract
Connecting a material's surface chemistry with its electrocatalytic performance is one of the major questions in analytical electrochemistry. This is especially important in many sensor applications where analytes from complex media need to be measured. Unfortunately, today this connection is still largely missing except perhaps for the most simple ideal model systems. Here we present an approach that can be used to obtain insights about this missing connection and apply it to the case of carbon nanomaterials. In this paper we show that by combining advanced computational techniques augmented by machine learning methods with x-ray absorption spectroscopy (XAS) and electrochemical measurements, it is possible to obtain a deeper understanding of the correlation between local surface chemistry and electrochemical performance. As a test case we show how by computationally assessing the growth of amorphous carbon (a-C) thin films at the atomic level, we can create computational structural motifs that may in turn be used to deconvolute the XAS data from the real samples resulting in local chemical information. Then, by carrying out electrochemical measurements on the same samples from which x-ray spectra were measured and that were further characterized computationally, it is possible to gain insight into the interplay between the local surface chemistry and electrochemical performance. To demonstrate this methodology, we proceed as follows: after assessing the basic electrochemical properties of a-C films, we investigate the effect of short HNO3treatment on the sensitivity of these electrodes towards an inner sphere redox probe dopamine to gain knowledge about the influence of altered surface chemistry to observed electrochemical performance. These results pave the way towards a more general assessment of electrocatalysis in different systems and provide the first steps towards data driven tailoring of electrode surfaces to gain optimal performance in a given application.
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Affiliation(s)
- Elli Leppänen
- Department of Electrical Engineering and Automation, School of Electrical Engineering, Aalto University, Tietotie 3, 02150 Espoo, Finland
| | - Anja Aarva
- Department of Electrical Engineering and Automation, School of Electrical Engineering, Aalto University, Tietotie 3, 02150 Espoo, Finland
| | - Sami Sainio
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, United States of America
- Microelectronics Research Unit, Faculty of Information Technology and Electrical Engineering, University of Oulu, PO Box. 4500, 90570 Oulu, Finland
| | - Miguel A Caro
- Department of Electrical Engineering and Automation, School of Electrical Engineering, Aalto University, Tietotie 3, 02150 Espoo, Finland
| | - Tomi Laurila
- Department of Electrical Engineering and Automation, School of Electrical Engineering, Aalto University, Tietotie 3, 02150 Espoo, Finland
- Department of Chemistry and Materials Science, Aalto University, Kemistintie 1, 02150 Espoo, Finland
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Huidobro J, Aramendia J, Arana G, Madariaga JM. Geochemical Characterization of the NWA 11273 Lunar Meteorite Using Nondestructive Analytical Techniques: Original, Shocked, and Alteration Mineral Phases. ACS Earth Space Chem 2021; 5:1333-1342. [PMID: 35673558 PMCID: PMC9165041 DOI: 10.1021/acsearthspacechem.0c00329] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 05/18/2021] [Accepted: 05/19/2021] [Indexed: 06/15/2023]
Abstract
A lunar feldspathic breccia meteorite, the Northwest Africa (NWA) 11273, was analyzed to compensate the lack of scientific data available about its mineralogy and geochemistry. In order to obtain a deeper characterization of the sample, a strategy based on the combination of nondestructive spectroscopic techniques such as X-ray fluorescence and Raman spectroscopy is used. Both techniques are being used in spatial missions by the Perseverance Rover, so their combination in the laboratory is here proposed as an optimal strategy to study the complete mineralogy of the sample. In addition to finding the minerals indicated by the Meteoritical Society (anorthite, olivine, pyroxene, kamacite, and troilite), other minor minerals were identified, such as zircon and ilmenite, which are minerals related to the Moon geology, as well as calcite and sulfate which can be considered products of terrestrial weathering. Finally, secondary minerals related to alteration processes were also found, such as hematite, quartz, and anatase. In this work, the alteration processes that gave rise to the detected secondary minerals have been proposed.
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Zhong W, Liu F, Wang C. Probing morphology and chemistry in complex soft materials with in situresonant soft x-ray scattering. J Phys Condens Matter 2021; 33:313001. [PMID: 34140434 DOI: 10.1088/1361-648x/ac0194] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 05/14/2021] [Indexed: 06/12/2023]
Abstract
Small angle scattering methodologies have been evolving at fast pace over the past few decades due to the ever-increasing demands for more details on the complex nanostructures of multiphase and multicomponent soft materials like polymer assemblies and biomaterials. Currently, element-specific and contrast variation techniques such as resonant (elastic) soft/tender x-ray scattering, anomalous small angle x-ray scattering, and contrast-matching small angle neutron scattering, or combinations of above are routinely used to extract the chemical composition and spatial arrangement of constituent elements at multiple length scales and examine electronic ordering phenomena. Here we present some recent advances in selectively characterizing structural architectures of complex soft materials, which often contain multi-components with a wide range of length scales and multiple functionalities, where novel resonant scattering approaches have been demonstrated to decipher a higher level of structural complexity that correlates to functionality. With the advancement of machine learning and artificial intelligence assisted correlative analysis, high-throughput and autonomous experiments would open a new paradigm of material research. Further development of resonant x-ray scattering instrumentation with crossplatform sample environments will enable multimodalin situ/operando characterization of the system dynamics with much improved spatial and temporal resolution.
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Affiliation(s)
- Wenkai Zhong
- Frontiers Science Center for Transformative Molecules, In-situ Center for Physical Science, and Center of Hydrogen Science, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States of America
| | - Feng Liu
- Frontiers Science Center for Transformative Molecules, In-situ Center for Physical Science, and Center of Hydrogen Science, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Cheng Wang
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States of America
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Hayama S, Boada R, Chaboy J, Birt A, Duller G, Cahill L, Freeman A, Amboage M, Keenan L, Diaz-Moreno S. Photon-in/photon-out spectroscopy at the I20-scanning beamline at diamond light source. J Phys Condens Matter 2021; 33:284003. [PMID: 33957610 DOI: 10.1088/1361-648x/abfe93] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 05/06/2021] [Indexed: 06/12/2023]
Abstract
A scanning multi-crystal x-ray emission spectrometer to perform photon-in/photon-out spectroscopy at the I20-Scanning beamline at Diamond Light Source is described. The instrument, equipped with three analyzer crystals, is based on a 1 m Rowland circle spectrometer operating in the vertical plane. The energy resolution of the spectrometer is of the order of 1 eV, having sufficient resolving power to overcome the core-hole lifetime broadening of most of the transition metalsK-edges. Examples showing the capability of the beamline for performing high energy resolution fluorescence detection x-ray absorption spectroscopy (HERFD-XAS), non-resonant x-ray emission spectroscopy (XES) and resonant x-ray emission spectroscopy are presented. The comparison of the Zn and MnK-edge HERFD-XANES of ZnO and MnO withab initiocalculations shows that the technique provides enhanced validation of the models by making subtle spectral features more visible.
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Affiliation(s)
- Shusaku Hayama
- Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Roberto Boada
- Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
- Department of Chemistry, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Jesús Chaboy
- Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Adrian Birt
- Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Graham Duller
- Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Leo Cahill
- Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Adam Freeman
- Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Monica Amboage
- Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Luke Keenan
- Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Sofia Diaz-Moreno
- Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
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Gann E, Crofts T, Holland G, Beaucage P, McAfee T, Kline RJ, Collins BA, McNeill CR, Fischer DA, DeLongchamp DM. A NIST facility for resonant soft x-ray scattering measuring nano-scale soft matter structure at NSLS-II. J Phys Condens Matter 2021; 33:164001. [PMID: 33498032 DOI: 10.1088/1361-648x/abdffb] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 01/26/2021] [Indexed: 06/12/2023]
Abstract
We present the design and performance of a polarized resonant soft x-ray scattering (RSoXS) station for soft matter characterization built by the national institute of standards and technology at the national synchrotron light source-II (NSLS-II). The RSoXS station is located within the spectroscopy soft and tender beamline suite at NSLS-II located in Brookhaven national laboratory, New York. Numerous elements of the RSoXS station were designed for optimal performance for measurements on soft matter systems, where it is of critical importance to minimize beam damage and maximize collection efficiency of polarized x-rays. These elements include a novel optical design, sample manipulator and sample environments, as well as detector setups. Finally, we will report the performance of the measurement station, including energy resolution, higher harmonic content and suppression methods, the extent and mitigation of the carbon absorption dip on optics, and the range of polarizations available from the elliptically polarized undulator source.
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Affiliation(s)
- Eliot Gann
- Materials Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States of America
| | - Thomas Crofts
- FMB-Oxford, Osney Mead, Oxford OX2 0ES, United Kingdom
| | - Glenn Holland
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States of America
| | - Peter Beaucage
- Materials Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States of America
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States of America
| | - Terry McAfee
- Department of Physics and Astronomy, Washington State University, Pullman, WA 99163, United States of America
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, United States of America
| | - R Joseph Kline
- Materials Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States of America
| | - Brian A Collins
- Department of Physics and Astronomy, Washington State University, Pullman, WA 99163, United States of America
| | - Christopher R McNeill
- Department of Materials Science and Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - Daniel A Fischer
- Materials Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States of America
| | - Dean M DeLongchamp
- Materials Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States of America
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14
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Garai D, Solokha V, Wilson A, Carlomagno I, Gupta A, Gupta M, Reddy VR, Meneghini C, Carla F, Morawe C, Zegenhagen J. Studying the onset of galvanic steel corrosion in situusing thin films: film preparation, characterization and application to pitting. J Phys Condens Matter 2021; 33:125001. [PMID: 33339007 DOI: 10.1088/1361-648x/abd523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 12/18/2020] [Indexed: 06/12/2023]
Abstract
This work reports about a novel approach for investigating surface processes during the early stages of galvanic corrosion of stainless steelin situby employing ultra-thin films and synchrotron x-radiation. Characterized by x-ray techniques and voltammetry, such films, sputter deposited from austenitic steel, were found representing useful replicas of the target material. Typical for stainless steel, the surface consists of a passivation layer of Fe- and Cr-oxides, a couple of nm thick, that is depleted of Ni. Films of ≈4 nm thickness were studiedin situin an electrochemical cell under potential control (-0.6 to +0.8 V vs Ag/AgCl) during exposure to 0.1 M KCl. Material transport was recorded with better than 1/10 monolayer sensitivity by x-ray spectroscopy. Leaching of Fe was observed in the cathodic range and the therefor necessary reduction of Fe-oxide appears to be accelerated by atomic hydrogen. Except for minor leaching, reduction of Ni, while expected from Pourbaix diagram, was not observed until at a potential of about +0.8 V Cr-oxide was removed from the steel film. After couple of minutes exposure at +0.8 V, the current in the electrochemical cell revealed a rapid pitting event that was simultaneously monitored by x-ray spectroscopy. Continuous loss of Cr and Ni was observed during the induction time leading to the pitting, suggesting a causal connection with the event. Finally, a spectroscopic image of a pit was recordedex situwith 50 nm lateral and 1 nm depth resolution by soft x-ray scanning absorption microscopy at the Fe L2,3-edges by using a 80 nm film on a SiN membrane, which is further demonstrating the usefulness of thin films for corrosion studies.
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Affiliation(s)
- Debi Garai
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom
- Amity Centre for Spintronic Materials, Amity University, Noida 201313, Uttar Pradesh, India
- Amity Institute of Applied Sciences, Amity University, Noida 201313, Uttar Pradesh, India
| | - Vladyslav Solokha
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom
- Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz, Austria
| | - Axel Wilson
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom
| | - Ilaria Carlomagno
- Dipartimento di Scienze, Universitá Roma Tre, Via della Vasca Navale 84, 00146 Rome, Italy
| | - Ajay Gupta
- Amity Centre for Spintronic Materials, Amity University, Noida 201313, Uttar Pradesh, India
| | - Mukul Gupta
- UGC-DAE CSR, DAVV campus, Khandwa Road, Indore 452017, Madhya Pradesh India
| | | | - Carlo Meneghini
- Dipartimento di Scienze, Universitá Roma Tre, Via della Vasca Navale 84, 00146 Rome, Italy
| | | | | | - Jörg Zegenhagen
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom
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15
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Al Fattah MF, Amin MR, Mallmann M, Kasap S, Schnick W, Moewes A. Electronic structure investigation of wide band gap semiconductors-Mg 2PN 3and Zn 2PN 3: experiment and theory. J Phys Condens Matter 2020; 32:405504. [PMID: 32364135 DOI: 10.1088/1361-648x/ab8f8a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Accepted: 05/01/2020] [Indexed: 06/11/2023]
Abstract
The research on nitridophosphate materials has gained significant attention in recent years due to the abundance of elements like Mg, Zn, P, and N. We present a detailed study of band gap and electronic structure of M2PN3(M = Mg, Zn), using synchrotron-based soft x-ray spectroscopy measurements as well as density functional theory (DFT) calculations. The experimental N K-edge x-ray emission spectroscopy (XES) and x-ray absorption spectroscopy (XAS) spectra are used to estimate the band gaps, which are compared with our calculations along with the values available in literature. The band gap, which is essential for electronic device applications, is experimentally determined for the first time to be 5.3 ± 0.2 eV and 4.2 ± 0.2 eV for Mg2PN3and Zn2PN3, respectively. The experimental band gaps agree well with our calculated band gaps of 5.4 eV for Mg2PN3and 3.9 eV for Zn2PN3, using the modified Becke-Johnson (mBJ) exchange potential. The states that contribute to the band gap are investigated with the calculated density of states especially with respect to two non-equivalent N sites in the structure. The calculations and the measurements predict that both materials have an indirect band gap. The wide band gap of M2PN3(M = Mg, Zn) could make it promising for the application in photovoltaic cells, high power RF applications, as well as power electronic devices.
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Affiliation(s)
- Md Fahim Al Fattah
- Department of Electrical and Computer Engineering, University of Saskatchewan, Saskatoon, Canada
| | - Muhammad Ruhul Amin
- Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Canada
| | - Mathias Mallmann
- Department of Chemistry, University of Munich (LMU), Butenandtstrasse, Munich, Germany
| | - Safa Kasap
- Department of Electrical and Computer Engineering, University of Saskatchewan, Saskatoon, Canada
| | - Wolfgang Schnick
- Department of Chemistry, University of Munich (LMU), Butenandtstrasse, Munich, Germany
| | - Alexander Moewes
- Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Canada
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16
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Brodusch N, Gauvin R. The qualitative f-ratio method applied to electron channelling-induced x-ray imaging with an annular silicon drift detector in a scanning electron microscope in the transmission mode. J Microsc 2017; 267:288-298. [PMID: 28421602 DOI: 10.1111/jmi.12565] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 02/10/2017] [Accepted: 03/21/2017] [Indexed: 11/30/2022]
Abstract
Electron channelling is known to affect the x-ray production when an accelerated electron beam is applied to a crystalline material and is highly dependent on the local crystal orientation. This effect, unless very long counting time are used, is barely noticeable on x-ray energy spectra recorded with conventional silicon drift detectors (SDD) located at a small elevation angle. However, the very high count rates provided by the new commercially available annular SDDs permit now to observe this effect routinely and may, in some circumstances, hide the true elemental x-ray variations due to the local true specimen composition. To circumvent this issue, the recently developed f-ratio method was applied to display qualitatively the true net intensity x-ray variations in a thin specimen of a Ti-6Al-4V alloy in a scanning electron microscope in transmission mode. The diffraction contrast observed in the x-ray images was successfully cancelled through the use of f-ratios and the true composition variations at the grain boundaries could be observed in relation to the dislocation alignment prior to the β-phase nucleation. The qualitative effectiveness in removing channelling effects demonstrated in this work makes the f-ratio, in its quantitative form, a possible alternative to the ZAF method in channelling conditions.
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Affiliation(s)
- Nicolas Brodusch
- Department of Mining and Materials Engineering, McGill University, Montréal, Québec, Canada
| | - Raynald Gauvin
- Department of Mining and Materials Engineering, McGill University, Montréal, Québec, Canada
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17
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Cao NM, Mier Valdivia AM, Rice JE. Applying X-ray Imaging Crystal Spectroscopy for Use as a High Temperature Plasma Diagnostic. J Vis Exp 2016:54408. [PMID: 27585305 PMCID: PMC5091949 DOI: 10.3791/54408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
X-ray spectra provide a wealth of information on high temperature plasmas; for example electron temperature and density can be inferred from line intensity ratios. By using a Johann spectrometer viewing the plasma, it is possible to construct profiles of plasma parameters such as density, temperature, and velocity with good spatial and time resolution. However, benchmarking atomic code modeling of X-ray spectra obtained from well-diagnosed laboratory plasmas is important to justify use of such spectra to determine plasma parameters when other independent diagnostics are not available. This manuscript presents the operation of the High Resolution X-ray Crystal Imaging Spectrometer with Spatial Resolution (HIREXSR), a high wavelength resolution spatially imaging X-ray spectrometer used to view hydrogen- and helium-like ions of medium atomic number elements in a tokamak plasma. In addition, this manuscript covers a laser blow-off system that can introduce such ions to the plasma with precise timing to allow for perturbative studies of transport in the plasma.
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Affiliation(s)
- Norman M Cao
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology
| | | | - John E Rice
- Plasma Science and Fusion Center, Massachusetts Institute of Technology;
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18
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Abstract
BACKGROUND The genus Aloe has been the subject of several chemotaxonomic and phytochemical investigations. Aloe ferox is an important source of biologically active compounds like anthrones, chromones, pyrones, and flavonoids. It is a plant used extensively in traditional medicine. Despite the myriad of studies on the pharmacological profile of the plant, there still exists a dearth of scientific literature on the anatomical and morphological attributes of this important medicinal plant. MATERIALS AND METHODS Hence, the objective of this study was to examine the foliar anatomy and micromorphological characteristics of A. ferox using light microscope and scanning electron microscope and to determine the elemental composition of the leaf sections by energy dispersive x-ray spectroscopy. RESULTS Epidermal cells varied from round, square to hexagonal, with distinctive anticlinal walls and sunken stomata, equally distributed on both the adaxial and abaxial surfaces were observed. There were vertically elongated palisade cells with numerous chloroplasts in the palisade mesophyll layer. The EDXS analysis revealed Ca, K, S, Al, Mg, and Si as the major constituents of crystals present in the mesophyll. CONCLUSION Information on the foliar anatomy and micromorphology can further enlightened our perceptions on the inherent interrelationships between structure and function as regards the synthesis and secretion of bioactive secondary metabolites by plants.
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Affiliation(s)
- Olubunmi Abosede Wintola
- Medicinal Plant and Economic Development Research Centre, Department of Botany, University of Fort Hare, South Africa
| | - Anthony Jide Afolayan
- Medicinal Plant and Economic Development Research Centre, Department of Botany, University of Fort Hare, South Africa
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19
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Ishimatsu N, Matsumoto K, Maruyama H, Kawamura N, Mizumaki M, Sumiya H, Irifune T. Glitch-free X-ray absorption spectrum under high pressure obtained using nano-polycrystalline diamond anvils. J Synchrotron Radiat 2012; 19:768-72. [PMID: 22898956 PMCID: PMC3621395 DOI: 10.1107/s0909049512026088] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 06/08/2012] [Indexed: 05/31/2023]
Abstract
Nano-polycrystalline diamond (NPD) [Irifune et al. (2003), Nature (London), 421, 599] has been used to obtain a glitch-free X-ray absorption spectrum under high pressure. In the case of conventional single-crystal diamond (SCD) anvils, glitches owing to Bragg diffraction from the anvils are superimposed on X-ray absorption spectra. The glitch has long been a serious problem for high-pressure research activities using X-ray spectroscopy because of the difficulties of its complete removal. It is demonstrated that NPD is one of the best candidate materials to overcome this problem. Here a glitch-free absorption spectrum using the NPD anvils over a wide energy range is shown. The advantage and capability of NPD anvils is discussed by a comparison of the glitch map with that of SCD anvils.
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Affiliation(s)
- Naoki Ishimatsu
- Department of Physics, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashihiroshima, Hiroshima 739-8526, Japan.
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20
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Bazzi M, Beer G, Bombelli L, Bragadireanu A, Cargnelli M, Curceanu (Petrascu) C, dʼUffizi A, Fiorini C, Frizzi T, Ghio F, Guaraldo C, Hayano R, Iliescu M, Ishiwatari T, Iwasaki M, Kienle P, Levi Sandri P, Longoni A, Marton J, Okada S, Pietreanu D, Ponta T, Rizzo A, Romero Vidal A, Sbardella E, Scordo A, Shi H, Sirghi D, Sirghi F, Tatsuno H, Tudorache A, Tudorache V, Vazquez Doce O, Wünschek B, Widmann E, Zmeskal J. Measurements of the strong-interaction widths of the kaonic (3)He and (4)He 2p levels. Phys Lett B 2012; 714:40-43. [PMID: 22876000 PMCID: PMC3405488 DOI: 10.1016/j.physletb.2012.06.071] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 06/06/2012] [Accepted: 06/26/2012] [Indexed: 06/01/2023]
Abstract
The kaonic (3)He and (4)He X-rays emitted in the [Formula: see text] transitions were measured in the SIDDHARTA experiment. The widths of the kaonic (3)He and (4)He 2p states were determined to be [Formula: see text], and [Formula: see text], respectively. Both results are consistent with the theoretical predictions. The width of kaonic (4)He is much smaller than the value of [Formula: see text] determined by the experiments performed in the 70's and 80's, while the width of kaonic (3)He was determined for the first time.
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Affiliation(s)
| | - M. Bazzi
- INFN, Laboratori Nazionali di Frascati, Frascati (Roma), Italy
| | - G. Beer
- Dep. of Phys. and Astro., Univ. of Victoria, Victoria B.C., Canada
| | - L. Bombelli
- Politecnico di Milano, Sez. di Elettronica, Milano, Italy
| | - A.M. Bragadireanu
- INFN, Laboratori Nazionali di Frascati, Frascati (Roma), Italy
- IFIN-HH, Magurele, Bucharest, Romania
| | - M. Cargnelli
- Stefan-Meyer-Institut für subatomare Physik, Vienna, Austria
| | | | - A. dʼUffizi
- INFN, Laboratori Nazionali di Frascati, Frascati (Roma), Italy
| | - C. Fiorini
- Politecnico di Milano, Sez. di Elettronica, Milano, Italy
| | - T. Frizzi
- Politecnico di Milano, Sez. di Elettronica, Milano, Italy
| | - F. Ghio
- INFN Sez. di Roma I and Inst. Superiore di Sanita, Roma, Italy
| | - C. Guaraldo
- INFN, Laboratori Nazionali di Frascati, Frascati (Roma), Italy
| | | | - M. Iliescu
- INFN, Laboratori Nazionali di Frascati, Frascati (Roma), Italy
- IFIN-HH, Magurele, Bucharest, Romania
| | - T. Ishiwatari
- Stefan-Meyer-Institut für subatomare Physik, Vienna, Austria
| | - M. Iwasaki
- RIKEN, The Inst. of Phys. and Chem. Research, Saitama, Japan
| | - P. Kienle
- Stefan-Meyer-Institut für subatomare Physik, Vienna, Austria
- Excellence Cluster Universe, Tech. Univ. München, Garching, Germany
| | - P. Levi Sandri
- INFN, Laboratori Nazionali di Frascati, Frascati (Roma), Italy
| | - A. Longoni
- Politecnico di Milano, Sez. di Elettronica, Milano, Italy
| | - J. Marton
- Stefan-Meyer-Institut für subatomare Physik, Vienna, Austria
| | - S. Okada
- RIKEN, The Inst. of Phys. and Chem. Research, Saitama, Japan
| | - D. Pietreanu
- INFN, Laboratori Nazionali di Frascati, Frascati (Roma), Italy
- IFIN-HH, Magurele, Bucharest, Romania
| | - T. Ponta
- IFIN-HH, Magurele, Bucharest, Romania
| | - A. Rizzo
- INFN, Laboratori Nazionali di Frascati, Frascati (Roma), Italy
| | - A. Romero Vidal
- INFN, Laboratori Nazionali di Frascati, Frascati (Roma), Italy
| | - E. Sbardella
- INFN, Laboratori Nazionali di Frascati, Frascati (Roma), Italy
| | - A. Scordo
- INFN, Laboratori Nazionali di Frascati, Frascati (Roma), Italy
| | - H. Shi
- Univ. of Tokyo, Tokyo, Japan
| | - D.L. Sirghi
- INFN, Laboratori Nazionali di Frascati, Frascati (Roma), Italy
- IFIN-HH, Magurele, Bucharest, Romania
| | - F. Sirghi
- INFN, Laboratori Nazionali di Frascati, Frascati (Roma), Italy
- IFIN-HH, Magurele, Bucharest, Romania
| | - H. Tatsuno
- INFN, Laboratori Nazionali di Frascati, Frascati (Roma), Italy
| | | | | | - O. Vazquez Doce
- Excellence Cluster Universe, Tech. Univ. München, Garching, Germany
| | - B. Wünschek
- Stefan-Meyer-Institut für subatomare Physik, Vienna, Austria
| | - E. Widmann
- Stefan-Meyer-Institut für subatomare Physik, Vienna, Austria
| | - J. Zmeskal
- Stefan-Meyer-Institut für subatomare Physik, Vienna, Austria
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21
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Karanfil C, Bunker G, Newville M, Segre CU, Chapman D. Quantitative performance measurements of bent crystal Laue analyzers for X-ray fluorescence spectroscopy. J Synchrotron Radiat 2012; 19:375-380. [PMID: 22514172 PMCID: PMC3329957 DOI: 10.1107/s0909049512003937] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Accepted: 01/30/2012] [Indexed: 05/31/2023]
Abstract
Third-generation synchrotron radiation sources pose difficult challenges for energy-dispersive detectors for XAFS because of their count rate limitations. One solution to this problem is the bent crystal Laue analyzer (BCLA), which removes most of the undesired scatter and fluorescence before it reaches the detector, effectively eliminating detector saturation due to background. In this paper experimental measurements of BCLA performance in conjunction with a 13-element germanium detector, and a quantitative analysis of the signal-to-noise improvement of BCLAs are presented. The performance of BCLAs are compared with filters and slits.
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Affiliation(s)
- C Karanfil
- Department of Physics, Faculty of Science, University of Muğla, Kötekli-Muğla 48187, Turkey.
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22
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Krmar M, Bucalović N, Baucal M, Jovančević N. Possible use of CdTe detectors in kVp monitoring of diagnostic x-ray tubes. Nucl Instrum Methods Phys Res A 2010; 622:256-260. [PMID: 21037976 PMCID: PMC2964844 DOI: 10.1016/j.nima.2010.07.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
It has been suggested that kVp of diagnostic X-ray devices (or maximal energy of x-ray photon spectra) should be monitored routinely; however a standardized noninvasive technique has yet to be developed and proposed. It is well known that the integral number of Compton scattered photons and the intensities of fluorescent x-ray lines registered after irradiation of some material by an x-ray beam are a function of the maximal beam energy. CdTe detectors have sufficient energy resolution to distinguish individual x-ray fluorescence lines and high efficiency for the photon energies in the diagnostic region. Our initial measurements have demonstrated that the different ratios of the integral number of Compton scattered photons and intensities of K and L fluorescent lines detected by CdTe detector are sensitive function of maximal photon energy and could be successfully applied for kVp monitoring.
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Affiliation(s)
- M Krmar
- Physics Department, University of Novi Sad, Novi Sad, Serbia
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23
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Beye M, Sorgenfrei F, Schlotter WF, Wurth W, Föhlisch A. The liquid-liquid phase transition in silicon revealed by snapshots of valence electrons. Proc Natl Acad Sci U S A 2010; 107:16772-6. [PMID: 20805512 PMCID: PMC2947918 DOI: 10.1073/pnas.1006499107] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The basis for the anomalies of water is still mysterious. Quite generally tetrahedrally coordinated systems, also silicon, show similar thermodynamic behavior but lack--like water--a thorough explanation. Proposed models--controversially discussed--explain the anomalies as a remainder of a first-order phase transition between high and low density liquid phases, buried deeply in the "no man's land"--a part of the supercooled liquid region where rapid crystallization prohibits any experimental access. Other explanations doubt the existence of the phase transition and its first-order nature. Here, we provide experimental evidence for the first-order-phase transition in silicon. With ultrashort optical pulses of femtosecond duration we instantaneously heat the electronic system of silicon while the atomic structure as defined by the much heavier nuclear system remains initially unchanged. Only on a picosecond time scale the energy is transferred into the atomic lattice providing the energy to drive the phase transitions. With femtosecond X-ray pulses from FLASH, the free-electron laser at Hamburg, we follow the evolution of the valence electronic structure during this process. As the relevant phases are easily distinguishable in their electronic structure, we track how silicon melts into the low-density-liquid phase while a second phase transition into the high-density-liquid phase only occurs after the latent heat for the first-order phase transition has been transferred to the atomic structure. Proving the existence of the liquid-liquid phase transition in silicon, the hypothesized liquid-liquid scenario for water is strongly supported.
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Affiliation(s)
- Martin Beye
- Institut für Experimentalphysik, Universität Hamburg and Centre for Free-Electron Laser Science, Luruper Chaussee 149, 22761 Hamburg, Germany.
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24
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Abstract
This review gives a brief description of the theory and application of X-ray absorption spectroscopy, both X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), especially, pertaining to photosynthesis. The advantages and limitations of the methods are discussed. Recent advances in extended EXAFS and polarized EXAFS using oriented membranes and single crystals are explained. Developments in theory in understanding the XANES spectra are described. The application of X-ray absorption spectroscopy to the study of the Mn(4)Ca cluster in Photosystem II is presented.
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Affiliation(s)
- Junko Yano
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720 USA
| | - Vittal K. Yachandra
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720 USA
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25
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Huang C, Wikfeldt KT, Tokushima T, Nordlund D, Harada Y, Bergmann U, Niebuhr M, Weiss TM, Horikawa Y, Leetmaa M, Ljungberg MP, Takahashi O, Lenz A, Ojamäe L, Lyubartsev AP, Shin S, Pettersson LGM, Nilsson A. The inhomogeneous structure of water at ambient conditions. Proc Natl Acad Sci U S A 2009; 106:15214-8. [PMID: 19706484 PMCID: PMC2741230 DOI: 10.1073/pnas.0904743106] [Citation(s) in RCA: 384] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2009] [Indexed: 11/18/2022] Open
Abstract
Small-angle X-ray scattering (SAXS) is used to demonstrate the presence of density fluctuations in ambient water on a physical length-scale of approximately 1 nm; this is retained with decreasing temperature while the magnitude is enhanced. In contrast, the magnitude of fluctuations in a normal liquid, such as CCl(4), exhibits no enhancement with decreasing temperature, as is also the case for water from molecular dynamics simulations under ambient conditions. Based on X-ray emission spectroscopy and X-ray Raman scattering data we propose that the density difference contrast in SAXS is due to fluctuations between tetrahedral-like and hydrogen-bond distorted structures related to, respectively, low and high density water. We combine our experimental observations to propose a model of water as a temperature-dependent, fluctuating equilibrium between the two types of local structures driven by incommensurate requirements for minimizing enthalpy (strong near-tetrahedral hydrogen-bonds) and maximizing entropy (nondirectional H-bonds and disorder). The present results provide experimental evidence that the extreme differences anticipated in the hydrogen-bonding environment in the deeply supercooled regime surprisingly remain in bulk water even at conditions ranging from ambient up to close to the boiling point.
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Affiliation(s)
- C. Huang
- Stanford Synchrotron Radiation Lightsource, P.O.B. 20450, Stanford, CA 94309
| | | | - T. Tokushima
- RIKEN/SPring-8, Sayo-cho, Sayo, Hyogo 679-5148, Japan
| | - D. Nordlund
- Stanford Synchrotron Radiation Lightsource, P.O.B. 20450, Stanford, CA 94309
| | - Y. Harada
- RIKEN/SPring-8, Sayo-cho, Sayo, Hyogo 679-5148, Japan
- Department of Applied Chemistry, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - U. Bergmann
- Stanford Synchrotron Radiation Lightsource, P.O.B. 20450, Stanford, CA 94309
| | - M. Niebuhr
- Stanford Synchrotron Radiation Lightsource, P.O.B. 20450, Stanford, CA 94309
| | - T. M. Weiss
- Stanford Synchrotron Radiation Lightsource, P.O.B. 20450, Stanford, CA 94309
| | - Y. Horikawa
- RIKEN/SPring-8, Sayo-cho, Sayo, Hyogo 679-5148, Japan
- Department of Physical Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | | | | | - O. Takahashi
- Department of Chemistry, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - A. Lenz
- Department of Chemistry, Linköping University, S-581 83 Linköping, Sweden; and
| | - L. Ojamäe
- Department of Chemistry, Linköping University, S-581 83 Linköping, Sweden; and
| | - A. P. Lyubartsev
- Division of Physical Chemistry, Stockholm University, S-10691 Stockholm, Sweden
| | - S. Shin
- RIKEN/SPring-8, Sayo-cho, Sayo, Hyogo 679-5148, Japan
- Institute for Solid State Physics, University of Tokyo, Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
| | | | - A. Nilsson
- Stanford Synchrotron Radiation Lightsource, P.O.B. 20450, Stanford, CA 94309
- FYSIKUM, AlbaNova, and
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26
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Abstract
Water oxidation to dioxygen in photosynthesis is catalyzed by a Mn(4)Ca cluster with O bridging in Photosystem II (PS II) of plants, algae and cyanobacteria. A variety of spectroscopic methods have been applied to analyzing the participation of the complex. X-ray spectroscopy is particularly useful because it is element-specific, and because it can reveal important structural features of the complex with high accuracy and identify the participation of Mn in the redox chemistry. Following a brief history of the application of X-ray spectroscopy to PS II, an overview of newer results will be presented and a description of the present state of our knowledge based on this approach.
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Affiliation(s)
- Kenneth Sauer
- Department of Chemistry, University of California, Berkeley, CA 94707-5230
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27
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Abstract
A detailed electronic structure of the Mn4Ca cluster is required before two key questions for understanding the mechanism of photosynthetic water oxidation can be addressed. They are whether all four oxidizing equivalents necessary to oxidize water to O2 accumulate on the four Mn ions of the oxygen-evolving complex, or do some ligand-centered oxidations take place before the formation and release of O2 during the S3 --> [S4] --> S0 transition, and what are the oxidation state assignments for the Mn during S-state advancement. X-ray absorption and emission spectroscopy of Mn, including the newly introduced resonant inelastic X-ray scattering spectroscopy have been used to address these questions. The present state of understanding of the electronic structure and oxidation state changes of the Mn4Ca cluster in all the S-states, particularly in the S2 to S3 transition, derived from these techniques is described in this review.
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Affiliation(s)
- Junko Yano
- Melvin Calvin Laboratory, Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Vittal K. Yachandra
- Melvin Calvin Laboratory, Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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28
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Sauer K, Yano J, Yachandra VK. X-ray spectroscopy of the Mn4Ca cluster in the water-oxidation complex of Photosystem II. Photosynth Res 2005; 85:73-86. [PMID: 15977060 PMCID: PMC3962501 DOI: 10.1007/s11120-005-0638-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2004] [Accepted: 01/13/2005] [Indexed: 05/03/2023]
Abstract
The water-oxidation complex of Photosystem II (PS II) contains a heteronuclear cluster of 4 Mn atoms and a Ca atom. Ligands to the metal cluster involve bridging O atoms, and O and N atoms from amino acid side-chains of the D1 polypeptide of PS II, with likely additional contributions from water and CP43. Although moderate resolution X-ray diffraction-based structures of PS II have been reported recently, and the location of the Mn4Ca cluster has been identified, the structures are not resolved at the atomic level. X-ray absorption (XAS), emission (XES), resonant inelastic X-ray scattering (RIXS) and extended X-ray absorption fine structure (EXAFS) provide independent and potentially highly accurate sources of structural and oxidation-state information. When combined with polarized X-ray studies of oriented membranes or single-crystals of PS II, a more detailed picture of the cluster and its disposition in PS II is obtained.
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Affiliation(s)
- Kenneth Sauer
- Department of Chemistry, University of California, Berkeley, CA 94720-1460, USA
- Melvin Calvin Laboratory, Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Authors for correspondence (; ; ; fax: +1-510-486-6059)
| | - Junko Yano
- Department of Chemistry, University of California, Berkeley, CA 94720-1460, USA
- Melvin Calvin Laboratory, Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Authors for correspondence (; ; ; fax: +1-510-486-6059)
| | - Vittal K. Yachandra
- Melvin Calvin Laboratory, Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Authors for correspondence (; ; ; fax: +1-510-486-6059)
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