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Kuila M, Mardegan J, Tayal A, Meneghini C, Francoual S, Raghavendra Reddy V. Sublattice spin reversal and field induced Fe 3+spin-canting across the magnetic compensation temperature in Y 1.5Gd 1.5Fe 5O 12rare-earth iron garnet. J Phys : Condens Matter 2023. [PMID: 37487492 DOI: 10.1088/1361-648x/acea11] [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] [Indexed: 07/26/2023]
Abstract
In the present work Fe\textsuperscript{3+} sublattice spin reversal and Fe\textsuperscript{3+} spin-canting across the magnetic compensation temperature (T\textsubscript{Comp}) are demonstrated in polycrystalline Y\textsubscript{1.5}Gd\textsubscript{1.5}Fe\textsubscript{5}O\textsubscript{12} (YGdIG) by means of in-field $^{57}Fe$ M$\ddot{o}$ssbauer spectroscopy measurements. Corroborating in-field $^{57}Fe$ M$\ddot{o}$ssbauer measurements, both Fe\textsuperscript{3+} \& Gd\textsuperscript{3+} sublattice spin reversal has also been manifested in hard x-ray magnetic circular dichroism (XMCD) measurements. From in-field $^{57}Fe$ M$\ddot{o}$ssbauer measurements, estimation and analysis of effective internal hyperfine field (H\textsubscript{eff}), relative intensity of absorption lines in a sextet elucidated unambiguously the signatures of Fe\textsuperscript{3+} spin reversal and field induced spin-canting of Fe\textsuperscript{3+} sublattices across T\textsubscript{Comp}. Gd L\textsubscript{3}-edge XMCD signal is observed to consist of an additional spectral feature, identified as Fe\textsuperscript{3+} magnetic contribution to XMCD spectra of Gd L\textsubscript{3}-edge, enabling us the extraction of both the sublattices (Fe\textsuperscript{3+} \& Gd\textsuperscript{3+}) information from a single absorption edge analysis. The evolution of the XMCD amplitudes, which is proportional to magnetic moments, as a function of temperature for both magnetic sublattices extracted at the Gd L\textsubscript{3}-edge reasonably match with values that are extracted from bulk magnetization data of YGdIG and YIG (Y\textsubscript{3}Fe\textsubscript{5}O\textsubscript{12}) and corresponding Fe K-edge XMCD amplitudes for Fe contribution. These measurements pave new avenues to investigate how the magnetic behavior of such complex system acts across the compensation point.
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Affiliation(s)
- Manik Kuila
- UGC DAE Consortium for Scientific Research, UGC DAE CSR, University Campus, Indore, Indore, Madhya Pradesh, 452017, INDIA
| | - Jose Mardegan
- DESY, Notkestraße 85,, Hamburg, Hamburg, 22607, GERMANY
| | - Akhil Tayal
- DESY, Notkestraße 85,, Hamburg, Hamburg, 22607, GERMANY
| | - Carlo Meneghini
- Dipartimento di Fisica 'E Amaldi', Universita degli Studi di Roma Tre, Via della Vasca Navale 84, 00146 Roma, Roma, I-00146, ITALY
| | - Sonia Francoual
- Photon Science, DESY, Notkestraße 85, Hamburg, Hamburg, 22607, GERMANY
| | - V Raghavendra Reddy
- UGC DAE Consortium for Scientific Research , UGC DAE CSR, University Campus, Khandwa Road, Indore- 452017, iNDORE, 452001, INDIA
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2
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Simeth W, Bauer A, Franz C, Aqeel A, Bereciartua PJ, Sears JA, Francoual S, Back CH, Pfleiderer C. Resonant Elastic X-Ray Scattering of Antiferromagnetic Superstructures in EuPtSi_{3}. Phys Rev Lett 2023; 130:266701. [PMID: 37450805 DOI: 10.1103/physrevlett.130.266701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 04/06/2023] [Accepted: 05/11/2023] [Indexed: 07/18/2023]
Abstract
We report resonant elastic x-ray scattering of long-range magnetic order in EuPtSi_{3}, combining different scattering geometries with full linear polarization analysis to unambiguously identify magnetic scattering contributions. At low temperatures, EuPtSi_{3} stabilizes type A antiferromagnetism featuring various long-wavelength modulations. For magnetic fields applied in the hard magnetic basal plane, well-defined regimes of cycloidal, conical, and fanlike superstructures may be distinguished that encompass a pocket of commensurate type A order without superstructure. For magnetic field applied along the easy axis, the phase diagram comprises the cycloidal and conical superstructures only. Highlighting the power of polarized resonant elastic x-ray scattering, our results reveal a combination of magnetic phases that suggest a highly unusual competition between antiferromagnetic exchange interactions with Dzyaloshinsky-Moriya spin-orbit coupling of similar strength.
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Affiliation(s)
- Wolfgang Simeth
- Physik-Department, Technische Universität München, D-85748 Garching, Germany
- Laboratory for Neutron and Muon Instrumentation, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - Andreas Bauer
- Physik-Department, Technische Universität München, D-85748 Garching, Germany
- Zentrum für QuantumEngineering (ZQE), Technische Universität München, D-85748 Garching, Germany
| | - Christian Franz
- Physik-Department, Technische Universität München, D-85748 Garching, Germany
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), D-85748 Garching, Germany
| | - Aisha Aqeel
- Physik-Department, Technische Universität München, D-85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Technische Universität München, D-85748 Garching, Germany
| | | | - Jennifer A Sears
- Deutsches Elektronen-Synchrotron (DESY), D-22607 Hamburg, Germany
| | - Sonia Francoual
- Deutsches Elektronen-Synchrotron (DESY), D-22607 Hamburg, Germany
| | - Christian H Back
- Physik-Department, Technische Universität München, D-85748 Garching, Germany
- Zentrum für QuantumEngineering (ZQE), Technische Universität München, D-85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Technische Universität München, D-85748 Garching, Germany
| | - Christian Pfleiderer
- Physik-Department, Technische Universität München, D-85748 Garching, Germany
- Zentrum für QuantumEngineering (ZQE), Technische Universität München, D-85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Technische Universität München, D-85748 Garching, Germany
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3
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Soh JR, Bombardi A, Mila F, Rahn MC, Prabhakaran D, Francoual S, Rønnow HM, Boothroyd AT. Understanding unconventional magnetic order in a candidate axion insulator by resonant elastic x-ray scattering. Nat Commun 2023; 14:3387. [PMID: 37296136 DOI: 10.1038/s41467-023-39138-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 05/30/2023] [Indexed: 06/12/2023] Open
Abstract
Magnetic topological insulators and semimetals are a class of crystalline solids whose properties are strongly influenced by the coupling between non-trivial electronic topology and magnetic spin configurations. Such materials can host exotic electromagnetic responses. Among these are topological insulators with certain types of antiferromagnetic order which are predicted to realize axion electrodynamics. Here we investigate the highly unusual helimagnetic phases recently reported in EuIn2As2, which has been identified as a candidate for an axion insulator. Using resonant elastic x-ray scattering we show that the two types of magnetic order observed in EuIn2As2 are spatially uniform phases with commensurate chiral magnetic structures, ruling out a possible phase-separation scenario, and we propose that entropy associated with low energy spin fluctuations plays a significant role in driving the phase transition between them. Our results establish that the magnetic order in EuIn2As2 satisfies the symmetry requirements for an axion insulator.
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Affiliation(s)
- Jian-Rui Soh
- Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | - Alessandro Bombardi
- Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot, Oxfordshire, UK
| | - Frédéric Mila
- Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Marein C Rahn
- Institute for Solid State and Materials Physics, Technical University of Dresden, Dresden, Germany
| | | | | | - Henrik M Rønnow
- Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Andrew T Boothroyd
- Department of Physics, University of Oxford, Clarendon Laboratory, Oxford, UK.
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4
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Deng Z, Wang X, Wang M, Shen F, Zhang J, Chen Y, Feng HL, Xu J, Peng Y, Li W, Zhao J, Wang X, Valvidares M, Francoual S, Leupold O, Hu Z, Tjeng LH, Li MR, Croft M, Zhang Y, Liu E, He L, Hu F, Sun J, Greenblatt M, Jin C. Giant Exchange-Bias-Like Effect at Low Cooling Fields Induced by Pinned Magnetic Domains in Y 2 NiIrO 6 Double Perovskite. Adv Mater 2023; 35:e2209759. [PMID: 36795948 DOI: 10.1002/adma.202209759] [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: 10/22/2022] [Revised: 02/06/2023] [Indexed: 05/17/2023]
Abstract
Exchange bias (EB) is highly desirable for widespread technologies. Generally, conventional exchange-bias heterojunctions require excessively large cooling fields for sufficient bias fields, which are generated by pinned spins at the interface of ferromagnetic and antiferromagnetic layers. It is crucial for applicability to obtain considerable exchange-bias fields with minimum cooling fields. Here, an exchange-bias-like effect is reported in a double perovskite, Y2 NiIrO6 , which shows long-range ferrimagnetic ordering below 192 K. It displays a giant bias-like field of 1.1 T with a cooling field of only 15 Oe at 5 K. This robust phenomenon appears below 170 K. This fascinating bias-like effect is the secondary effect of the vertical shifts of the magnetic loops, which is attributed to the pinned magnetic domains due to the combination of strong spin-orbit coupling on Ir, and antiferromagnetically coupled Ni- and Ir-sublattices. The pinned moments in Y2 NiIrO6 are present throughout the full volume, not just at the interface as in conventional bilayer systems.
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Affiliation(s)
- Zheng Deng
- Institute of Physics, Chinese Academy of Sciences, School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
- Department of Chemistry and Chemical Biology, Rutgers the State University of New Jersey, 123 Bevier Road, Piscataway, NJ, 08854, USA
| | - Xiao Wang
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straβe 40, Dresden, 01187, Dresden, Germany
| | - Mengqin Wang
- Institute of Physics, Chinese Academy of Sciences, School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Feiran Shen
- Spallation Neutron Source Science Center, Institute of High Energy Physics, Chinese Academy of Sciences, Dongguan, 523803, P. R. China
| | - Jine Zhang
- Institute of Physics, Chinese Academy of Sciences, School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Yuansha Chen
- Institute of Physics, Chinese Academy of Sciences, School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Hai L Feng
- Institute of Physics, Chinese Academy of Sciences, School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Jiawang Xu
- Institute of Physics, Chinese Academy of Sciences, School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Yi Peng
- Institute of Physics, Chinese Academy of Sciences, School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Wenmin Li
- Institute of Physics, Chinese Academy of Sciences, School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Jianfa Zhao
- Institute of Physics, Chinese Academy of Sciences, School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Xiancheng Wang
- Institute of Physics, Chinese Academy of Sciences, School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Manuel Valvidares
- ALBA Synchrotron Light Source, Cerdanyola del Valles, Barcelona, 08290, Spain
| | - Sonia Francoual
- Deutsches Elektronen-Synchrotron (DESY), Notkestraße 85, Hamburg, 22607, Hamburg, Germany
| | - Olaf Leupold
- Deutsches Elektronen-Synchrotron (DESY), Notkestraße 85, Hamburg, 22607, Hamburg, Germany
| | - Zhiwei Hu
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straβe 40, Dresden, 01187, Dresden, Germany
| | - Liu Hao Tjeng
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straβe 40, Dresden, 01187, Dresden, Germany
| | - Man-Rong Li
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, P. R. China
| | - Mark Croft
- Department of Physics and Astronomy, Rutgers the State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ, 08854, USA
| | - Ying Zhang
- Institute of Physics, Chinese Academy of Sciences, School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Enke Liu
- Institute of Physics, Chinese Academy of Sciences, School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Lunhua He
- Institute of Physics, Chinese Academy of Sciences, School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
- Spallation Neutron Source Science Center, Songshan Lake Materials Laboratory, Dongguan, 523808, P. R. China
| | - Fengxia Hu
- Institute of Physics, Chinese Academy of Sciences, School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Jirong Sun
- Institute of Physics, Chinese Academy of Sciences, School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Martha Greenblatt
- Department of Chemistry and Chemical Biology, Rutgers the State University of New Jersey, 123 Bevier Road, Piscataway, NJ, 08854, USA
| | - Changqing Jin
- Institute of Physics, Chinese Academy of Sciences, School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
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5
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Laksman J, Dietrich F, Liu J, Maltezopoulos T, Planas M, Freund W, Gautam R, Kujala N, Francoual S, Grünert J. Development of a photoelectron spectrometer for hard x-ray photon diagnostics. Rev Sci Instrum 2022; 93:115111. [PMID: 36461550 DOI: 10.1063/5.0097525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 10/21/2022] [Indexed: 06/17/2023]
Abstract
The development and characterization of an angle-resolved photoelectron spectrometer, based on the electron time-of-flight concept, for hard x-ray photon diagnostics at the European Free-Electron Laser, are described. The instrument is meant to provide users and operators with pulse-resolved, non-invasive spectral distribution diagnostics, which in the hard x-ray regime is a challenge due to the poor cross-section and high kinetic energy of photoelectrons for the available target gases. We report on the performances of this instrument as obtained using hard x-rays at the PETRA III synchrotron at DESY in multibunch mode. Results are compared with electron trajectory simulations. We demonstrate a resolving power of 10 eV at incident photon energies up to at least 20 keV.
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Affiliation(s)
| | | | - Jia Liu
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | | | - Marc Planas
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | | | | | - Naresh Kujala
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Sonia Francoual
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
| | - Jan Grünert
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
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6
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Spitz L, Nomoto T, Kitou S, Nakao H, Kikkawa A, Francoual S, Taguchi Y, Arita R, Tokura Y, Arima TH, Hirschberger M. Entropy-Assisted, Long-Period Stacking of Honeycomb Layers in an AlB 2-Type Silicide. J Am Chem Soc 2022; 144:16866-16871. [PMID: 36066406 DOI: 10.1021/jacs.2c04995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Configurational entropy can impact crystallization processes, tipping the scales between structures of nearly equal internal energy. Using alloyed single crystals of Gd2PdSi3 in the AlB2-type structure, we explore the formation of complex layer sequences made from alternating, two-dimensional triangular and honeycomb slabs. A four-period and an eight-period stacking sequence are found to be very close in internal energy, the latter being favored by entropy associated with covering the full configuration space of interlayer bonds. Possible consequences of polytype formation on magnetism in Gd2PdSi3 are discussed.
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Affiliation(s)
- Leonie Spitz
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
| | - Takuya Nomoto
- Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Shunsuke Kitou
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
| | - Hironori Nakao
- Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801, Japan
| | - Akiko Kikkawa
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
| | - Sonia Francoual
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
| | - Yasujiro Taguchi
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
| | - Ryotaro Arita
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan.,Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Yoshinori Tokura
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan.,Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan.,Tokyo College, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Taka-Hisa Arima
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan.,Department of Advanced Materials Science, University of Tokyo, Kashiwa, Chiba 277-8561, Japan
| | - Max Hirschberger
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan.,Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
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7
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Liu Z, Zhang S, Wang X, Ye X, Qin S, Shen X, Lu D, Dai J, Cao Y, Chen K, Radu F, Wu WB, Chen CT, Francoual S, Mardegan JRL, Leupold O, Tjeng LH, Hu Z, Yang YF, Long Y. Realization of a Half Metal with a Record-High Curie Temperature in Perovskite Oxides. Adv Mater 2022; 34:e2200626. [PMID: 35231130 DOI: 10.1002/adma.202200626] [Citation(s) in RCA: 2] [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: 01/20/2022] [Revised: 02/19/2022] [Indexed: 06/14/2023]
Abstract
Half metals, in which one spin channel is conducting while the other is insulating with an energy gap, are theoretically considered to comprise 100% spin-polarized conducting electrons, and thus have promising applications in high-efficiency magnetic sensors, computer memory, magnetic recording, and so on. However, for practical applications, a high Curie temperature combined with a wide spin energy gap and large magnetization is required. Realizing such a high-performance combination is a key challenge. Herein, a novel A- and B-site ordered quadruple perovskite oxide LaCu3 Fe2 Re2 O12 with the charge format of Cu2+ /Fe3+ /Re4.5+ is reported. The strong Cu2+ (↑)Fe3+ (↑)Re4.5+ (↓) spin interactions lead to a ferrimagnetic Curie temperature as high as 710 K, which is the reported record in perovskite-type half metals thus far. The saturated magnetic moment determined at 300 K is 7.0 μB f.u.-1 and further increases to 8.0 μB f.u.-1 at 2 K. First-principles calculations reveal a half-metallic nature with a spin-down conducting band while a spin-up insulating band with a large energy gap up to 2.27 eV. The currently unprecedented realization of record Curie temperature coupling with the wide energy gap and large moment in LaCu3 Fe2 Re2 O12 opens a way for potential applications in advanced spintronic devices at/above room temperature.
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Affiliation(s)
- Zhehong Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shuaikang Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiao Wang
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187, Dresden, Germany
| | - Xubin Ye
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shijun Qin
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xudong Shen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China
| | - Dabiao Lu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jianhong Dai
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yingying Cao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Kai Chen
- Helmholtz-Zentrum Berlin fur Materialien und Energie, Albert-Einstein-Str.15, 12489, Berlin, Germany
| | - Florin Radu
- Helmholtz-Zentrum Berlin fur Materialien und Energie, Albert-Einstein-Str.15, 12489, Berlin, Germany
| | - Wen-Bin Wu
- National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan
| | - Chien-Te Chen
- National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan
| | - Sonia Francoual
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607, Hamburg, Germany
| | - José R L Mardegan
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607, Hamburg, Germany
| | - Olaf Leupold
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607, Hamburg, Germany
| | - Liu Hao Tjeng
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187, Dresden, Germany
| | - Zhiwei Hu
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187, Dresden, Germany
| | - Yi-Feng Yang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China
| | - Youwen Long
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China
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8
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Takagi R, Matsuyama N, Ukleev V, Yu L, White JS, Francoual S, Mardegan JRL, Hayami S, Saito H, Kaneko K, Ohishi K, Ōnuki Y, Arima TH, Tokura Y, Nakajima T, Seki S. Square and rhombic lattices of magnetic skyrmions in a centrosymmetric binary compound. Nat Commun 2022; 13:1472. [PMID: 35354812 PMCID: PMC8967868 DOI: 10.1038/s41467-022-29131-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 03/01/2022] [Indexed: 11/29/2022] Open
Abstract
Magnetic skyrmions are topologically stable swirling spin textures with particle-like character, and have been intensively studied as a candidate of high-density information bit. While magnetic skyrmions were originally discovered in noncentrosymmetric systems with Dzyaloshinskii-Moriya interaction, recently a nanometric skyrmion lattice has also been reported for centrosymmetric rare-earth compounds, such as Gd2PdSi3 and GdRu2Si2. For the latter systems, a distinct skyrmion formation mechanism mediated by itinerant electrons has been proposed, and the search of a simpler model system allowing for a better understanding of their intricate magnetic phase diagram is highly demanded. Here, we report the discovery of square and rhombic lattices of nanometric skyrmions in a centrosymmetric binary compound EuAl4, by performing small-angle neutron and resonant elastic X-ray scattering experiments. Unlike previously reported centrosymmetric skyrmion-hosting materials, EuAl4 shows multiple-step reorientation of the fundamental magnetic modulation vector as a function of magnetic field, probably reflecting a delicate balance of associated itinerant-electron-mediated interactions. The present results demonstrate that a variety of distinctive skyrmion orders can be derived even in a simple centrosymmetric binary compound, which highlights rare-earth intermetallic systems as a promising platform to realize/control the competition of multiple topological magnetic phases in a single material. Typically, skyrmions appear in magnet systems which are non-centrosymmetric. Here, using neutron and X-ray scattering, Takagi et al show the emergence of a skyrmion phase in the centrosymmetric material EuAl4. This expands the range of materials potential hosting skyrmions.
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Affiliation(s)
- Rina Takagi
- Department of Applied Physics, University of Tokyo, Tokyo, 113-8656, Japan. .,Institute of Engineering Innovation, University of Tokyo, Tokyo, 113-0032, Japan. .,PRESTO, Japan Science and Technology Agency (JST), Kawaguchi, 332-0012, Japan. .,RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198, Japan.
| | - Naofumi Matsuyama
- Department of Applied Physics, University of Tokyo, Tokyo, 113-8656, Japan
| | - Victor Ukleev
- Laboratory for Neutron Scattering and Imaging (LNS), Paul Scherrer Institute (PSI), 5232, Villigen, Switzerland
| | - Le Yu
- Laboratory for Neutron Scattering and Imaging (LNS), Paul Scherrer Institute (PSI), 5232, Villigen, Switzerland.,Laboratory for Ultrafast Microscopy and Electron Scattering (LUMES), Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.,Laboratory of Nanoscale Magnetic Materials and Magnonics (LMGN), Institute of Materials, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Jonathan S White
- Laboratory for Neutron Scattering and Imaging (LNS), Paul Scherrer Institute (PSI), 5232, Villigen, Switzerland
| | - Sonia Francoual
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607, Hamburg, Germany
| | - José R L Mardegan
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607, Hamburg, Germany
| | - Satoru Hayami
- Department of Applied Physics, University of Tokyo, Tokyo, 113-8656, Japan.,PRESTO, Japan Science and Technology Agency (JST), Kawaguchi, 332-0012, Japan
| | - Hiraku Saito
- The Institute for Solid State Physics, University of Tokyo, Kashiwa, 277-8561, Japan
| | - Koji Kaneko
- Materials Sciences Research Center, Japan Atomic Energy Agency, Tokai, 319-1195, Japan.,J-PARC Center, Japan Atomic Energy Agency, Tokai, 319-1195, Japan
| | - Kazuki Ohishi
- Neutron Science and Technology Center, Comprehensive Research Organization for Science and Society (CROSS), Tokai, 319-1106, Japan
| | - Yoshichika Ōnuki
- RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198, Japan
| | - Taka-Hisa Arima
- RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198, Japan.,Department of Advanced Materials Science, University of Tokyo, Kashiwa, 277-8561, Japan
| | - Yoshinori Tokura
- Department of Applied Physics, University of Tokyo, Tokyo, 113-8656, Japan.,RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198, Japan.,Tokyo College, University of Tokyo, Tokyo, 113-8656, Japan
| | - Taro Nakajima
- RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198, Japan.,The Institute for Solid State Physics, University of Tokyo, Kashiwa, 277-8561, Japan
| | - Shinichiro Seki
- Department of Applied Physics, University of Tokyo, Tokyo, 113-8656, Japan.,Institute of Engineering Innovation, University of Tokyo, Tokyo, 113-0032, Japan.,PRESTO, Japan Science and Technology Agency (JST), Kawaguchi, 332-0012, Japan.,RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198, Japan
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9
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Al-Humaidi M, Feigl L, Jakob J, Schroth P, AlHassan A, Davtyan A, Herranz J, Anjum T, Novikov D, Francoual S, Geelhaar L, Baumbach T, Pietsch U. In situx-ray analysis of misfit strain and curvature of bent polytypic GaAs-In xGa 1-xAs core-shell nanowires. Nanotechnology 2021; 33:015601. [PMID: 34560680 DOI: 10.1088/1361-6528/ac29d8] [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: 05/06/2021] [Accepted: 09/24/2021] [Indexed: 06/13/2023]
Abstract
Misfit strain in core-shell nanowires can be elastically released by nanowire bending in case of asymmetric shell growth around the nanowire core. In this work, we investigate the bending of GaAs nanowires during the asymmetric overgrowth by an InxGa1-xAs shell caused by avoiding substrate rotation. We observe that the nanowire bending direction depends on the nature of the substrate's oxide layer, demonstrated by Si substrates covered by native and thermal oxide layers. Further, we follow the bending evolution by time-resolvedin situx-ray diffraction measurements during the deposition of the asymmetric shell. The XRD measurements give insight into the temporal development of the strain as well as the bending evolution in the core-shell nanowire.
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Affiliation(s)
- Mahmoud Al-Humaidi
- Solid State Physics, University of Siegen, Walter-Flex Straße 3, D-57068, Siegen, Germany
- Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany
| | - Ludwig Feigl
- Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany
| | - Julian Jakob
- Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany
- Laboratory for Applications of Synchrotron Radiation, Karlsruhe Institute of Technology, Kaiserstraße 12, D-76131 Karlsruhe, Germany
| | - Philipp Schroth
- Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany
- Laboratory for Applications of Synchrotron Radiation, Karlsruhe Institute of Technology, Kaiserstraße 12, D-76131 Karlsruhe, Germany
| | - Ali AlHassan
- Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany
| | - Arman Davtyan
- Solid State Physics, University of Siegen, Walter-Flex Straße 3, D-57068, Siegen, Germany
| | - Jesús Herranz
- Paul-Drude-Institut für Festkörperelektronik, Leibniz Institut im Forschungsverbund Berlin e.V., Hausvogteiplatz 5-7, 10117 Berlin, Germany
| | - Tasser Anjum
- Solid State Physics, University of Siegen, Walter-Flex Straße 3, D-57068, Siegen, Germany
| | - Dmitri Novikov
- Deutsches Elektronen-Synchrotron, PETRA III, D-22607 Hamburg, Germany
| | - Sonia Francoual
- Deutsches Elektronen-Synchrotron, PETRA III, D-22607 Hamburg, Germany
| | - Lutz Geelhaar
- Paul-Drude-Institut für Festkörperelektronik, Leibniz Institut im Forschungsverbund Berlin e.V., Hausvogteiplatz 5-7, 10117 Berlin, Germany
| | - Tilo Baumbach
- Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany
- Laboratory for Applications of Synchrotron Radiation, Karlsruhe Institute of Technology, Kaiserstraße 12, D-76131 Karlsruhe, Germany
| | - Ullrich Pietsch
- Solid State Physics, University of Siegen, Walter-Flex Straße 3, D-57068, Siegen, Germany
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10
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Kim JH, Peets DC, Reehuis M, Adler P, Maljuk A, Ritschel T, Allison MC, Geck J, Mardegan JRL, Bereciartua Perez PJ, Francoual S, Walters AC, Keller T, Abdala PM, Pattison P, Dosanjh P, Keimer B. Hidden Charge Order in an Iron Oxide Square-Lattice Compound. Phys Rev Lett 2021; 127:097203. [PMID: 34506205 DOI: 10.1103/physrevlett.127.097203] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 08/04/2021] [Indexed: 06/13/2023]
Abstract
Since the discovery of charge disproportionation in the FeO_{2} square-lattice compound Sr_{3}Fe_{2}O_{7} by Mössbauer spectroscopy more than fifty years ago, the spatial ordering pattern of the disproportionated charges has remained "hidden" to conventional diffraction probes, despite numerous x-ray and neutron scattering studies. We have used neutron Larmor diffraction and Fe K-edge resonant x-ray scattering to demonstrate checkerboard charge order in the FeO_{2} planes that vanishes at a sharp second-order phase transition upon heating above 332 K. Stacking disorder of the checkerboard pattern due to frustrated interlayer interactions broadens the corresponding superstructure reflections and greatly reduces their amplitude, thus explaining the difficulty of detecting them by conventional probes. We discuss the implications of these findings for research on "hidden order" in other materials.
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Affiliation(s)
- Jung-Hwa Kim
- Max-Planck-Institut für Festkörperforschung, D-70569 Stuttgart, Germany
| | - Darren C Peets
- Max-Planck-Institut für Festkörperforschung, D-70569 Stuttgart, Germany
- Ningbo Institute for Materials Technology and Engineering, Chinese Academy of Sciences, Zhenhai, Ningbo, 315201 Zhejiang, China
- Institut für Festkörper- und Materialphysik, Technische Universität Dresden, D-01069 Dresden, Germany
| | - Manfred Reehuis
- Helmholtz-Zentrum Berlin für Materialien und Energie, D-14109 Berlin, Germany
| | - Peter Adler
- Max-Planck-Institut für Chemische Physik fester Stoffe, D-01187 Dresden, Germany
| | - Andrey Maljuk
- Max-Planck-Institut für Festkörperforschung, D-70569 Stuttgart, Germany
- Leibniz Institut für Festkörper- und Werkstoffforschung, D-01171 Dresden, Germany
| | - Tobias Ritschel
- Institut für Festkörper- und Materialphysik, Technische Universität Dresden, D-01069 Dresden, Germany
| | - Morgan C Allison
- Institut für Festkörper- und Materialphysik, Technische Universität Dresden, D-01069 Dresden, Germany
| | - Jochen Geck
- Institut für Festkörper- und Materialphysik, Technische Universität Dresden, D-01069 Dresden, Germany
- Würzburg-Dresden Cluster of Excellence ct.qmat, Technische Universität Dresden, 01062 Dresden, Germany
| | | | | | - Sonia Francoual
- Deutsches Elektronen-Synchrotron DESY, Hamburg 22603, Germany
| | - Andrew C Walters
- Max-Planck-Institut für Festkörperforschung, D-70569 Stuttgart, Germany
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - Thomas Keller
- Max-Planck-Institut für Festkörperforschung, D-70569 Stuttgart, Germany
- Max Planck Society Outstation at the Heinz Maier-Leibnitz Zentrum (MLZ), D-85748 Garching, Germany
| | | | - Philip Pattison
- SNBL at ESRF, BP 220, F-38042 Grenoble Cedex 9, France
- Laboratory for Quantum Magnetism, École polytechnique fédérale de Lausanne (EPFL), BSP-Dorigny, CH-1015 Lausanne, Switzerland
| | - Pinder Dosanjh
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1 Canada
| | - Bernhard Keimer
- Max-Planck-Institut für Festkörperforschung, D-70569 Stuttgart, Germany
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11
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Bereciartua PJ, Rodríguez-Carvajal J, Francoual S. MagStREXS: crystallographic software for magnetic structure determination through resonant X-ray magnetic diffraction data. Acta Crystallogr A Found Adv 2021. [DOI: 10.1107/s0108767321095052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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12
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Strizhevsky E, Borodin D, Schori A, Francoual S, Röhlsberger R, Shwartz S. Efficient Interaction of Heralded X-Ray Photons with a Beam Splitter. Phys Rev Lett 2021; 127:013603. [PMID: 34270298 DOI: 10.1103/physrevlett.127.013603] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Accepted: 05/27/2021] [Indexed: 06/13/2023]
Abstract
We report the experimental demonstration of efficient interaction of multi-kilo-electron-volt heralded x-ray photons with a beam splitter. The measured heralded photon rate at the outputs of the beam splitter is about 0.01 counts/s which is comparable to the rate in the absence of the beam splitter. We use this beam splitter together with photon number and photon energy resolving detectors to show directly that when a single x-ray photon interacts with a beam splitter it can only be detected at either of the ports of the beam splitter but not at both simultaneously, leading to a strong anticorrelation between the detection events at the two output ports. Our experiment demonstrates the major advantage of x rays for quantum optics-the possibility to observe experimental results with high fidelity and with negligible background.
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Affiliation(s)
- E Strizhevsky
- Physics Department and Institute of Nanotechnology, Bar-Ilan University, Ramat Gan 5290002, Israel
| | - D Borodin
- Physics Department and Institute of Nanotechnology, Bar-Ilan University, Ramat Gan 5290002, Israel
| | - A Schori
- Physics Department and Institute of Nanotechnology, Bar-Ilan University, Ramat Gan 5290002, Israel
- PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - S Francoual
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22607 Hamburg, Germany
| | - R Röhlsberger
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22607 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - S Shwartz
- Physics Department and Institute of Nanotechnology, Bar-Ilan University, Ramat Gan 5290002, Israel
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13
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Liu Y, Luchini A, Martí-Sánchez S, Koch C, Schuwalow S, Khan SA, Stankevič T, Francoual S, Mardegan JRL, Krieger JA, Strocov VN, Stahn J, Vaz CAF, Ramakrishnan M, Staub U, Lefmann K, Aeppli G, Arbiol J, Krogstrup P. Coherent Epitaxial Semiconductor-Ferromagnetic Insulator InAs/EuS Interfaces: Band Alignment and Magnetic Structure. ACS Appl Mater Interfaces 2020; 12:8780-8787. [PMID: 31877013 DOI: 10.1021/acsami.9b15034] [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] [Indexed: 06/10/2023]
Abstract
Hybrid semiconductor-ferromagnetic insulator heterostructures are interesting due to their tunable electronic transport, self-sustained stray field, and local proximitized magnetic exchange. In this work, we present lattice-matched hybrid epitaxy of semiconductor-ferromagnetic insulator InAs/EuS heterostructures and analyze the atomic-scale structure and their electronic and magnetic characteristics. The Fermi level at the InAs/EuS interface is found to be close to the InAs conduction band and in the band gap of EuS, thus preserving the semiconducting properties. Both neutron and X-ray reflectivity measurements show that the overall ferromagnetic component is mainly localized in the EuS thin film with a suppression of the Eu moment in the EuS layer nearest the InAs and magnetic moments outside the detection limits on the pure InAs side. This work presents a step toward realizing defect-free semiconductor-ferromagnetic insulator epitaxial hybrids for spin-lifted quantum and spintronic applications without external magnetic fields.
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Affiliation(s)
- Yu Liu
- Microsoft Quantum Materials Lab Copenhagen , 2800 Lyngby , Denmark
| | | | - Sara Martí-Sánchez
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST , Campus UAB, Bellaterra , 08193 Barcelona , Catalonia , Spain
| | - Christian Koch
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST , Campus UAB, Bellaterra , 08193 Barcelona , Catalonia , Spain
| | - Sergej Schuwalow
- Microsoft Quantum Materials Lab Copenhagen , 2800 Lyngby , Denmark
| | - Sabbir A Khan
- Microsoft Quantum Materials Lab Copenhagen , 2800 Lyngby , Denmark
| | - Tomaš Stankevič
- Microsoft Quantum Materials Lab Copenhagen , 2800 Lyngby , Denmark
| | - Sonia Francoual
- Deutsches Elektronen-Synchrotron DESY , Hamburg 22603 , Germany
| | | | | | | | - Jochen Stahn
- Paul Scherrer Institute , CH-5232 Villigen , Switzerland
| | - Carlos A F Vaz
- Paul Scherrer Institute , CH-5232 Villigen , Switzerland
| | | | - Urs Staub
- Paul Scherrer Institute , CH-5232 Villigen , Switzerland
| | | | - Gabriel Aeppli
- Paul Scherrer Institute , CH-5232 Villigen , Switzerland
- ETH , CH-8093 Zürich , Switzerland
- EPFL , CH-1015 Lausanne , Switzerland
| | - Jordi Arbiol
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST , Campus UAB, Bellaterra , 08193 Barcelona , Catalonia , Spain
- ICREA , Pg. Lluís Companys 23 , 08010 Barcelona , Catalonia , Spain
| | - Peter Krogstrup
- Microsoft Quantum Materials Lab Copenhagen , 2800 Lyngby , Denmark
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14
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Bereciartua PJ, Francoual S, Mardegan JRL, Sears J, Rodríguez-Carvajal J, Picca FE. MagStReX: magnetic structures through resonant X-ray scattering. Acta Crystallogr A Found Adv 2019. [DOI: 10.1107/s2053273319091605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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15
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Suzuki H, Gretarsson H, Ishikawa H, Ueda K, Yang Z, Liu H, Kim H, Kukusta D, Yaresko A, Minola M, Sears JA, Francoual S, Wille HC, Nuss J, Takagi H, Kim BJ, Khaliullin G, Yavaş H, Keimer B. Spin waves and spin-state transitions in a ruthenate high-temperature antiferromagnet. Nat Mater 2019; 18:563-567. [PMID: 30911120 DOI: 10.1038/s41563-019-0327-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 02/26/2019] [Indexed: 06/09/2023]
Abstract
Ruthenium compounds serve as a platform for fundamental concepts such as spin-triplet superconductivity1, Kitaev spin liquids2-5 and solid-state analogues of the Higgs mode in particle physics6,7. However, basic questions about the electronic structure of ruthenates remain unanswered, because several key parameters (including Hund's coupling, spin-orbit coupling and exchange interactions) are comparable in magnitude and their interplay is poorly understood, partly due to difficulties in synthesizing large single crystals for spectroscopic experiments. Here we introduce a resonant inelastic X-ray scattering (RIXS)8,9 technique capable of probing collective modes in microcrystals of 4d electron materials. We observe spin waves and spin-state transitions in the honeycomb antiferromagnet SrRu2O6 (ref. 10) and use the extracted exchange interactions and measured magnon gap to explain its high Néel temperature11-16. We expect that the RIXS method presented here will enable momentum-resolved spectroscopy of a large class of 4d transition-metal compounds.
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Affiliation(s)
- H Suzuki
- Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany.
| | - H Gretarsson
- Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
| | - H Ishikawa
- Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
- Institut für Funktionelle Materie und Quantentechnologien, Universität Stuttgart, Stuttgart, Germany
| | - K Ueda
- Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
- Department of Applied Physics, University of Tokyo, Tokyo, Japan
| | - Z Yang
- Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
| | - H Liu
- Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
| | - H Kim
- Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
- Department of Physics, Pohang University of Science and Technology, Pohang, South Korea
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, South Korea
| | - D Kukusta
- Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
| | - A Yaresko
- Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
| | - M Minola
- Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
| | - J A Sears
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
| | - S Francoual
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
| | - H-C Wille
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
| | - J Nuss
- Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
| | - H Takagi
- Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
- Institut für Funktionelle Materie und Quantentechnologien, Universität Stuttgart, Stuttgart, Germany
- Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - B J Kim
- Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
- Department of Physics, Pohang University of Science and Technology, Pohang, South Korea
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, South Korea
| | - G Khaliullin
- Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
| | - H Yavaş
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - B Keimer
- Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany.
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16
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Haber J, Gollwitzer J, Francoual S, Tolkiehn M, Strempfer J, Röhlsberger R. Spectral Control of an X-Ray L-Edge Transition via a Thin-Film Cavity. Phys Rev Lett 2019; 122:123608. [PMID: 30978038 DOI: 10.1103/physrevlett.122.123608] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 02/13/2019] [Indexed: 06/09/2023]
Abstract
By embedding a thin layer of tantalum in an x-ray cavity, we observe a change in the spectral characteristics of an inner-shell transition of the metal. The interaction between the cavity mode vacuum and the L_{III}-edge transition is enhanced, permitting the observation of the collective Lamb shift, superradiance, and a Fano-like cavity-resonance interference effect. This experiment demonstrates the feasibility of cavity quantum electrodynamics with electronic resonances in the x-ray range with applications to manipulating and probing the electronic structure of condensed matter with high-resolution x-ray spectroscopy in an x-ray cavity setting.
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Affiliation(s)
- Johann Haber
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
| | - Jakob Gollwitzer
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
| | - Sonia Francoual
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
| | - Martin Tolkiehn
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
| | - Jörg Strempfer
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
| | - Ralf Röhlsberger
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
- The Hamburg Center for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany
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17
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Bereciartua PJ, Mardegan JRL, Francoual S, Rosa P, Rodríguez-Carvajal J, Veiga LSI, Picca FE, Saleta M, Strempfer J. Magnetic structure determination of EuPtIn 4 through resonant X-ray magnetic scattering. Acta Crystallogr A Found Adv 2018. [DOI: 10.1107/s2053273318093695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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18
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Hejral U, Franz D, Volkov S, Francoual S, Strempfer J, Stierle A. Identification of a Catalytically Highly Active Surface Phase for CO Oxidation over PtRh Nanoparticles under Operando Reaction Conditions. Phys Rev Lett 2018; 120:126101. [PMID: 29694082 DOI: 10.1103/physrevlett.120.126101] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Indexed: 05/20/2023]
Abstract
Pt-Rh alloy nanoparticles on oxide supports are widely employed in heterogeneous catalysis with applications ranging from automotive exhaust control to energy conversion. To improve catalyst performance, an atomic-scale correlation of the nanoparticle surface structure with its catalytic activity under industrially relevant operando conditions is essential. Here, we present x-ray diffraction data sensitive to the nanoparticle surface structure combined with in situ mass spectrometry during near ambient pressure CO oxidation. We identify the formation of ultrathin surface oxides by detecting x-ray diffraction signals from particular nanoparticle facets and correlate their evolution with the sample's enhanced catalytic activity. Our approach opens the door for an in-depth characterization of well-defined, oxide-supported nanoparticle based catalysts under operando conditions with unprecedented atomic-scale resolution.
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Affiliation(s)
- U Hejral
- Deutsches Elektronen-Synchrotron DESY, 22603 Hamburg, Germany
- Fachbereich Physik, Universität Hamburg, 20355 Hamburg, Germany
- Synchrotron Radiation Research, Lund University, 22100 Lund, Sweden
| | - D Franz
- Deutsches Elektronen-Synchrotron DESY, 22603 Hamburg, Germany
- Fachbereich Physik, Universität Hamburg, 20355 Hamburg, Germany
| | - S Volkov
- Deutsches Elektronen-Synchrotron DESY, 22603 Hamburg, Germany
- Fachbereich Physik, Universität Hamburg, 20355 Hamburg, Germany
| | - S Francoual
- Deutsches Elektronen-Synchrotron DESY, 22603 Hamburg, Germany
| | - J Strempfer
- Deutsches Elektronen-Synchrotron DESY, 22603 Hamburg, Germany
| | - A Stierle
- Deutsches Elektronen-Synchrotron DESY, 22603 Hamburg, Germany
- Fachbereich Physik, Universität Hamburg, 20355 Hamburg, Germany
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19
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Francoual S, Strempfer J, Warren J, Liu Y, Skaugen A, Poli S, Blume J, Wolff-Fabris F, Canfield PC, Lograsso T. Single-crystal X-ray diffraction and resonant X-ray magnetic scattering at helium-3 temperatures in high magnetic fields at beamline P09 at PETRA III. J Synchrotron Radiat 2015; 22:1207-1214. [PMID: 26289272 DOI: 10.1107/s1600577515014149] [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: 01/30/2015] [Accepted: 07/27/2015] [Indexed: 06/04/2023]
Abstract
The resonant scattering and diffraction beamline P09 at PETRA III at DESY is equipped with a 14 T vertical field split-pair magnet. A helium-3 refrigerator is available that can be fitted inside the magnet's variable-temperature insert. Here the results of a series of experiments aimed at determining the beam conditions permitting operations with the He-3 insert are presented. By measuring the tetragonal-to-orthorhombic phase transition occurring at 2.1 K in the Jahn-Teller compound TmVO4, it is found that the photon flux at P09 must be attenuated down to 1.5 × 10(9) photons s(-1) for the sample to remain at temperatures below 800 mK. Despite such a reduction of the incident flux and the subsequent use of a Cu(111) analyzer, the resonant X-ray magnetic scattering signal at the Tm LIII absorption edge associated with the spin-density wave in TmNi2B2C below 1.5 K is intense enough to permit a complete study in magnetic field and at sub-Kelvin temperatures to be carried out.
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Affiliation(s)
- S Francoual
- Deutsches Elektronen-Synchrotron (DESY), 22603 Hamburg, Germany
| | - J Strempfer
- Deutsches Elektronen-Synchrotron (DESY), 22603 Hamburg, Germany
| | - J Warren
- Cryogenic Ltd, London W3 7QE, UK
| | - Y Liu
- Division of Materials Sciences and Engineering (DMSE), Ames Laboratory, US DOE, Ames, IA 50010, USA
| | - A Skaugen
- Deutsches Elektronen-Synchrotron (DESY), 22603 Hamburg, Germany
| | - S Poli
- Cryogenic Ltd, London W3 7QE, UK
| | - J Blume
- Deutsches Elektronen-Synchrotron (DESY), 22603 Hamburg, Germany
| | - F Wolff-Fabris
- Hochfeld-Magnetlabor Dresden (HLD), Helmholtz-Zentrum Dresden-Rossendorf, D-01314 Dresden, Germany
| | - P C Canfield
- Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011, USA
| | - T Lograsso
- Division of Materials Sciences and Engineering (DMSE), Ames Laboratory, US DOE, Ames, IA 50010, USA
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Kuschel T, Klewe C, Schmalhorst JM, Bertram F, Kuschel O, Schemme T, Wollschläger J, Francoual S, Strempfer J, Gupta A, Meinert M, Götz G, Meier D, Reiss G. Static Magnetic Proximity Effect in Pt/NiFe2O4 and Pt/Fe Bilayers Investigated by X-Ray Resonant Magnetic Reflectivity. Phys Rev Lett 2015; 115:097401. [PMID: 26371679 DOI: 10.1103/physrevlett.115.097401] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Indexed: 06/05/2023]
Abstract
The spin polarization of Pt in Pt/NiFe2O4 and Pt/Fe bilayers is studied by interface-sensitive x-ray resonant magnetic reflectivity to investigate static magnetic proximity effects. The asymmetry ratio of the reflectivity is measured at the Pt L3 absorption edge using circular polarized x-rays for opposite directions of the magnetization at room temperature. The results of the 2% asymmetry ratio for Pt/Fe bilayers are independent of the Pt thickness between 1.8 and 20 nm. By comparison with ab initio calculations, the maximum magnetic moment per spin polarized Pt atom at the interface is determined to be (0.6±0.1) μB for Pt/Fe. For Pt/NiFe2O4 the asymmetry ratio drops below the sensitivity limit of 0.02 μB per Pt atom. Therefore, we conclude, that the longitudinal spin Seebeck effect recently observed in Pt/NiFe2O4 is not influenced by a proximity induced anomalous Nernst effect.
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Affiliation(s)
- T Kuschel
- Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - C Klewe
- Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - J-M Schmalhorst
- Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - F Bertram
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
| | - O Kuschel
- Fachbereich Physik, Universität Osnabrück, Barbarastraße 7, 49069 Osnabrück, Germany
| | - T Schemme
- Fachbereich Physik, Universität Osnabrück, Barbarastraße 7, 49069 Osnabrück, Germany
| | - J Wollschläger
- Fachbereich Physik, Universität Osnabrück, Barbarastraße 7, 49069 Osnabrück, Germany
| | - S Francoual
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
| | - J Strempfer
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
| | - A Gupta
- Center for Materials for Information Technology, University of Alabama, Tuscaloosa, Alabama 35487, USA
| | - M Meinert
- Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - G Götz
- Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - D Meier
- Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - G Reiss
- Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
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Strempfer J, Francoual S, Reuther D, Shukla DK, Skaugen A, Schulte-Schrepping H, Kracht T, Franz H. Resonant scattering and diffraction beamline P09 at PETRA III. J Synchrotron Radiat 2013; 20:541-549. [PMID: 23765295 DOI: 10.1107/s0909049513009011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 04/02/2013] [Indexed: 05/27/2023]
Abstract
The resonant scattering and diffraction beamline P09 at PETRA III is designed for X-ray experiments requiring small beams, energy tunability, variable polarization and high photon flux. It is highly flexible in terms of beam size and offers full higher harmonic suppression. A state-of-the-art double phase-retarder set-up provides variable linear or circular polarization. A high-precision Psi-diffractometer and a heavy-load diffractometer in horizontal Psi-geometry allow the accommodation of a wide variety of sample environments. A 14 T cryo-magnet is available for scattering experiments in magnetic fields.
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Affiliation(s)
- J Strempfer
- Deutsches Elektronen-Synchrotron (DESY), 22603 Hamburg, Germany.
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Correa VF, Francoual S, Jaime M, Harrison N, Murphy TP, Palm EC, Tozer SW, Lacerda AH, Sharma PA, Mydosh JA. High-magnetic-field lattice length changes in URu2Si2. Phys Rev Lett 2012; 109:246405. [PMID: 23368353 DOI: 10.1103/physrevlett.109.246405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Indexed: 06/01/2023]
Abstract
We report high-magnetic-field (up to 45 T) ĉ-axis thermal-expansion and magnetostriction experiments on URu(2)Si(2) single crystals. The sample length change ΔL(c)(T(HO))/L(c) associated with the transition to the "hidden order" phase becomes increasingly discontinuous as the magnetic field is raised above 25 T. The reentrant ordered phase III is clearly observed in both the thermal expansion ΔL(c)(T)/L(c) and magnetostriction ΔL(c)(B)/L(c) above 36 T, in good agreement with previous results. The sample length is also discontinuous at the boundaries of this phase, mainly at the upper boundary. A change in the sign of the coefficient of thermal expansion α(c)=1/L(c)(∂ΔL(c)/∂T) is observed at the metamagnetic transition (B(M) ~ 38 T), which is likely related to the existence of a quantum critical end point.
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Affiliation(s)
- V F Correa
- Centro Atómico Bariloche, CNEA, and Instituto Balseiro, UN Cuyo, 8400 Bariloche, Río Negro, Argentina
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Abstract
Abstract
We present here simulation results on the dynamical structure factor of the C14 Laves Phase of MgZn2, the simplest of the Mg–(Al,Zn) Frank-Kasper alloy phases. The dynamical structure factor was determined in two ways. Firstly, the dynamical matrix was obtained in harmonic approximation from ab-initio forces. The dynamical structure factor can then be computed from the eigenvalues of the dynamical matrix. Alternatively, Molecular Dynamics simulations of a larger sample were used to measure the correlation function corresponding to the dynamical structure factor. Both results are compared to data from neutron scattering experiments. This comparison also includes the intensity distribution, which is a very sensitive test. We find that the dynamical structure factor determined with either method agrees reasonably well with the experiment. In particular, the intensity transfer from acoustic to optic phonon modes can be reproduced correctly. This shows that simulation studies can complement phonon dispersion measurements.
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Affiliation(s)
| | - Marc de Boissieu
- UMR CNRS 5614, ENSEEG-INPG-UJF, Laboratoire de Thermodynamique et Physico-Chimie M, St. Martin dHères Cedex, Frankreich
| | | | - Sonia Francoual
- Laboratoire de Thermodynamique et Physico-Chimie Métallurgique, UMR CNRS 5614, ENSEEG-INPG-UJF, St. Martin dHères Cedex, Frankreich
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Abstract
Abstract
We review results obtained in the study of the diffuse scattering in the i-AlPdMn quasicrystal. Most of the diffuse scattering is the result of long wavelength phason modes. The shape and intensity distribution of the diffuse scattering is well reproduced using the generalised elasticity theory and two phason elastic constants. The temperature dependence of the diffuse scattering indicates a softening of the phason elastic constant as the temperature is lowered. Using coherent X-rays and photo-correlation X-ray spectroscopy, it is shown that phason modes are collective diffusive modes, in agreement with the hydrodynamic theory of long wavelength fluctuations in quasicrystals.
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Affiliation(s)
| | - Sonia Francoual
- Laboratoire de Thermodynamique et Physico-Chimie Métallurgique, UMR CNRS 5614, ENSEEG-INPG-UJF, St. Martin dHères Cedex, Frankreich
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Wolff-Fabris F, Francoual S, Zapf V, Jaime M, Scott B, Tozer S, Hannahs S, Murphy T, Lacerda A. Magnetostriction and thermal expansion on 1D quantum spin system azurite. ACTA ACUST UNITED AC 2009. [DOI: 10.1088/1742-6596/150/4/042030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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De Boissieu M, Mihalkovic M, Francoual S, Shibata K, Takakura H, Ishimasa T, Tsai AP. Atomic simulation and lattice dynamics of the ZnMgSc icosahedral quasicrystal. Acta Crystallogr A 2008. [DOI: 10.1107/s010876730809541x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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de Boissieu M, Francoual S, Mihalkovic M, Shibata K, Baron AQR, Sidis Y, Ishimasa T, Wu D, Lograsso T, Regnault LP, Gähler F, Tsutsui S, Hennion B, Bastie P, Sato TJ, Takakura H, Currat R, Tsai AP. Lattice dynamics of the Zn-Mg-Sc icosahedral quasicrystal and its Zn-Sc periodic 1/1 approximant. Nat Mater 2007; 6:977-984. [PMID: 17982466 DOI: 10.1038/nmat2044] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2007] [Accepted: 09/26/2007] [Indexed: 05/25/2023]
Abstract
Quasicrystals are long-range-ordered materials that lack translational invariance, so the study of their physical properties remains a challenging problem. Here, we have carried out inelastic-X-ray- and neutron-scattering experiments on single-grain samples of the Zn-Mg-Sc icosahedral quasicrystal and of the Zn-Sc periodic cubic 1/1 approximant, with the aim of studying the respective influence of the local order and of the long-range order (periodic or quasiperiodic) on lattice dynamics. Besides the overall similarities and the existence of a pseudo-gap in the transverse dispersion relation, marked differences are observed, the pseudo-gap being larger and better defined in the approximant than in the quasicrystal. This can be qualitatively explained using the concept of a pseudo-Brillouin-zone in the quasicrystal. These results are compared with simulations on atomic models and using oscillating pair potentials, and the simulations reproduce in detail the experimental results. This paves the way for a detailed understanding of the physics of quasicrystals.
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Affiliation(s)
- Marc de Boissieu
- Sciences et Ingénierie des Matériaux et Procédés, INPGrenoble CNRS UJF, BP 75 38402 St Martin d'Hères Cedex, France.
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de Boissieu M, Francoual S, Kaneko Y, Ishimasa T. Diffuse scattering and phason fluctuations in the Zn-Mg-Sc icosahedral quasicrystal and its Zn-Sc periodic approximant. Phys Rev Lett 2005; 95:105503. [PMID: 16196940 DOI: 10.1103/physrevlett.95.105503] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2005] [Revised: 07/21/2005] [Indexed: 05/04/2023]
Abstract
We report on the absolute scale measurement of the x-ray diffuse scattering in the ZnMgSc icosahedral quasicrystal and its periodic approximant. Whereas the diffuse scattering in the approximant is purely accounted for by thermal diffuse scattering, an additional signal is observed in the quasicrystal. It is related to phason fluctuations as indicated by its Q(2)(per) dependence. Moreover, when compared to previous measurements carried out on the i-AlPdMn phase, we find that the amount of diffuse scattering is smaller in the i-ZnMgSc phase, in agreement with larger phason elastic constants in this phase. This is confirmed by the observation of a large number of weak Bragg peaks having a high Q(per) reciprocal space component.
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Affiliation(s)
- M de Boissieu
- Laboratoire de Thermodynamique et de Physico-Chimie Métallurgique, UMR CNRS 5614, ENSEEG-INPG, Saint Martin d'Hères, France.
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de Boissieu M, Ishimas T, Francoual S. Diffuse scattering and phasons in the i-Zn-Mg-Sc phase and its 1/1 approximant. Acta Crystallogr A 2005. [DOI: 10.1107/s0108767305098387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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30
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Francoual S, Livet F, de Boissieu M, Yakhou F, Bley F, Létoublon A, Caudron R, Gastaldi J. Dynamics of phason fluctuations in the i-AlPdMn quasicrystal. Phys Rev Lett 2003; 91:225501. [PMID: 14683248 DOI: 10.1103/physrevlett.91.225501] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2003] [Indexed: 05/24/2023]
Abstract
We report on the study of the dynamics of long wavelength phason fluctuations in the i-AlPdMn icosahedral phase using coherent x-ray scattering. When measured with a coherent x-ray beam, the diffuse intensity due to phasons presents strong fluctuations or speckles pattern. From room temperature to 500 degrees C the speckle pattern is time independent. At 650 degrees C the time correlation of the speckle pattern exhibits an exponential time decay, from which a characteristic time tau is extracted. We find that tau is proportional to the square of the phason wavelength, which demonstrates that phasons are collective diffusive modes in quasicrystals, in agreement with theoretical predictions.
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Affiliation(s)
- S Francoual
- Laboratoire de Thermodynamique et de Physico-Chimie Métallurgique, UMR CNRS 5614, ENSEEG-INPG, BP 75, 38402 Saint Martin d'Hères Cedex, France
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Timsit JF, Misset B, Francoual S, Goldstein FW, Vaury P, Carlet J. Is protected specimen brush a reproducible method to diagnose ICU-acquired pneumonia? Chest 1993; 104:104-8. [PMID: 8325050 DOI: 10.1378/chest.104.1.104] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
UNLABELLED Protected specimen brush (PSB) is considered to be one of the standard methods for the diagnosis of ventilator-associated pneumonia, but to our knowledge, intraindividual variability in results has not been reported previously. PURPOSE To compare the results of two PSB performed in the same subsegment on patients with suspected ICU-acquired pneumonia (IAP). STUDY DESIGN Between October 1991 and April 1992, each mechanically ventilated patient with suspected IAP underwent bronchoscopy with two successive PSB in the lung segment identified as abnormal on radiographs. Results of the two PSB cultures were compared using 10(3) cfu/ml cutoff for a positive result. Four definite diagnoses were established during the follow up: definite pneumonia, probable pneumonia, excluded pneumonia, and uncertain pneumonia. POPULATION Forty-two episodes in 26 patients were studied; 60 percent of patients received prior antibiotic therapy. Thirty-two microorganisms were isolated from 24 pairs of PSB. Definite diagnosis was definite pneumonia in 7, probable pneumonia in 8, excluded pneumonia in 17, and uncertain pneumonia in 10 cases. RESULTS The PSB recovered the same microorganisms and argued for a good qualitative reproducibility. The distinction of positive and negative results on the basis of the 10(3) cfu/ml classic threshold was less reproducible. For 24 percent of the microorganisms recovered and in 16.7 percent of episodes of suspected IAP, the two consecutive samples gave results spread out on each side of the 10(3) cfu/ml cutoff. Discordance was higher when definite diagnosis was certain or probable than when diagnosis was excluded (p = 0.015). There was no statistical effect of the order of samples between the two specimens for bacterial index and microorganism concentrations. CONCLUSION These findings argue for the poor repeatability of PSB in suspected IAP and question the yield of the 10(3) cfu/ml threshold. In attempting to diagnose IAP, the results of PSB must be interpreted with caution considering the intraindividual variability.
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Affiliation(s)
- J F Timsit
- Intensive Care Unit, Hôpital Saint Joseph, Paris, France
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Mainardi JL, Boyer JM, Francoual S, Goldstein F, Farkas JC, Laurian C, Acar JF. [Periprosthetic popliteal abscess caused by Listeria monocytogenes]. Presse Med 1993; 22:36. [PMID: 8469664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
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Astagneau P, Goldstein FW, Francoual S, Baviera E, Barthalon M, Acar JF. Appendicitis due to both Streptococcus pneumoniae and Haemophilus influenzae. Eur J Clin Microbiol Infect Dis 1992; 11:559-60. [PMID: 1526244 DOI: 10.1007/bf01960816] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Gutmann L, Billot-Klein D, al-Obeid S, Klare I, Francoual S, Collatz E, van Heijenoort J. Inducible carboxypeptidase activity in vancomycin-resistant enterococci. Antimicrob Agents Chemother 1992; 36:77-80. [PMID: 1534213 PMCID: PMC189230 DOI: 10.1128/aac.36.1.77] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Vancomycin was found to coinduce DD-carboxypeptidase activity, together with resistance, in eight low- or high-level glycopeptide-resistant strains of enterococci. The constitutively resistant mutant (MT10) of a low-level-resistant strain of Enterococcus faecium (D366) spontaneously expressed a level of carboxypeptidase similar to that of the induced strain D366. Pentapeptide, UDP-MurNac-pentapeptide, as well as D-alanyl-D-alanine were in vitro substrates for the carboxypeptidase which was not inhibited by penicillin. The level of vancomycin resistance correlated roughly with the level of carboxypeptidase activity. We infer from these results that the carboxypeptidase is one component of the glycopeptide resistance mechanism.
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Affiliation(s)
- L Gutmann
- Laboratoire de Microbiologie Médicale, Université Paris VI, France
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Francoual S, Lamy P, Le Quintrec Y, Luboinski J, Petit JC. Helicobacter pylori: has it a part in the lesion of the gastroesophageal reflux? J Infect Dis 1990; 162:1414-5. [PMID: 2230279 DOI: 10.1093/infdis/162.6.1414] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
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Abstract
Clinical problems of bacterial resistance to the new fluoroquinolones are emerging as their use increases. Emergence of resistant strains has been observed in various types of infections, especially of the respiratory tract. Only limited studies, however, deal with strains isolated from clinical specimens. The identity between the original strain and the resistant variant is rarely proved. Resistance to quinolones can be due to a modification in DNA gyrase or to an alteration in outer membrane permeability (pleiotropic resistance). Methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa have been recognized as species at risk of developing such resistance. Strategies to minimize the emergence of resistance are discussed.
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Affiliation(s)
- J F Acar
- Hôpital Saint-Joseph, Laboratoire de Microbiologie Médicale, France
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Bonnefoy A, Luboinski J, Francoual S, Gueho E, Drouhet E, Bertiere M, Petit J. Un cas de phaeohyphomycose du a Phialophora richardsiae. Med Mal Infect 1988. [DOI: 10.1016/s0399-077x(88)80061-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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