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Abdukayumov K, Mičica M, Ibrahim F, Vojáček L, Vergnaud C, Marty A, Veuillen JY, Mallet P, de Moraes IG, Dosenovic D, Gambarelli S, Maurel V, Wright A, Tignon J, Mangeney J, Ouerghi A, Renard V, Mesple F, Li J, Bonell F, Okuno H, Chshiev M, George JM, Jaffrès H, Dhillon S, Jamet M. Atomic-Layer Controlled Transition from Inverse Rashba-Edelstein Effect to Inverse Spin Hall Effect in 2D PtSe 2 Probed by THz Spintronic Emission. Adv Mater 2024; 36:e2304243. [PMID: 38160244 DOI: 10.1002/adma.202304243] [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: 05/06/2023] [Revised: 11/09/2023] [Indexed: 01/03/2024]
Abstract
2D materials, such as transition metal dichalcogenides, are ideal platforms for spin-to-charge conversion (SCC) as they possess strong spin-orbit coupling (SOC), reduced dimensionality and crystal symmetries as well as tuneable band structure, compared to metallic structures. Moreover, SCC can be tuned with the number of layers, electric field, or strain. Here, SCC in epitaxially grown 2D PtSe2 by THz spintronic emission is studied since its 1T crystal symmetry and strong SOC favor SCC. High quality of as-grown PtSe2 layers is demonstrated, followed by in situ ferromagnet deposition by sputtering that leaves the PtSe2 unaffected, resulting in well-defined clean interfaces as evidenced with extensive characterization. Through this atomic growth control and using THz spintronic emission, the unique thickness-dependent electronic structure of PtSe2 allows the control of SCC. Indeed, the transition from the inverse Rashba-Edelstein effect (IREE) in 1-3 monolayers (ML) to the inverse spin Hall effect (ISHE) in multilayers (>3 ML) of PtSe2 enabling the extraction of the perpendicular spin diffusion length and relative strength of IREE and ISHE is demonstrated. This band structure flexibility makes PtSe2 an ideal candidate to explore the underlying mechanisms and engineering of the SCC as well as for the development of tuneable THz spintronic emitters.
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Affiliation(s)
- Khasan Abdukayumov
- CEA, CNRS, Université Grenoble Alpes, Grenoble INP, IRIG-Spintec, Grenoble, 38000, France
| | - Martin Mičica
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, Paris, 75005, France
| | - Fatima Ibrahim
- CEA, CNRS, Université Grenoble Alpes, Grenoble INP, IRIG-Spintec, Grenoble, 38000, France
| | - Libor Vojáček
- CEA, CNRS, Université Grenoble Alpes, Grenoble INP, IRIG-Spintec, Grenoble, 38000, France
| | - Céline Vergnaud
- CEA, CNRS, Université Grenoble Alpes, Grenoble INP, IRIG-Spintec, Grenoble, 38000, France
| | - Alain Marty
- CEA, CNRS, Université Grenoble Alpes, Grenoble INP, IRIG-Spintec, Grenoble, 38000, France
| | - Jean-Yves Veuillen
- CNRS, Université Grenoble Alpes, Grenoble INP-UGA, Institut NéeL, Grenoble, 38000, France
| | - Pierre Mallet
- CNRS, Université Grenoble Alpes, Grenoble INP-UGA, Institut NéeL, Grenoble, 38000, France
| | | | | | - Serge Gambarelli
- CEA, CNRS, IRIG-SYMMES, Université Grenoble Alpes, Grenoble, 38000, France
| | - Vincent Maurel
- CEA, CNRS, IRIG-SYMMES, Université Grenoble Alpes, Grenoble, 38000, France
| | - Adrien Wright
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, Paris, 75005, France
| | - Jérôme Tignon
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, Paris, 75005, France
| | - Juliette Mangeney
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, Paris, 75005, France
| | - Abdelkarim Ouerghi
- CNRS, Centre de Nanosciences et de Nanotechnologies, Université Paris-Saclay, Palaiseau, 91120, France
| | - Vincent Renard
- CEA, IRIG-Pheliqs, Université Grenoble Alpes, Grenoble, 38000, France
| | - Florie Mesple
- CEA, IRIG-Pheliqs, Université Grenoble Alpes, Grenoble, 38000, France
| | - Jing Li
- CEA, Leti, Université Grenoble Alpes, Grenoble, 38000, France
| | - Frédéric Bonell
- CEA, CNRS, Université Grenoble Alpes, Grenoble INP, IRIG-Spintec, Grenoble, 38000, France
| | - Hanako Okuno
- CEA, IRIG-MEM, Université Grenoble Alpes, Grenoble, 38000, France
| | - Mairbek Chshiev
- CEA, CNRS, Université Grenoble Alpes, Grenoble INP, IRIG-Spintec, Grenoble, 38000, France
- Institut Universitaire de France, Paris, 75231, France
| | - Jean-Marie George
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, Palaiseau, F-91767, France
| | - Henri Jaffrès
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, Palaiseau, F-91767, France
| | - Sukhdeep Dhillon
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, Paris, 75005, France
| | - Matthieu Jamet
- CEA, CNRS, Université Grenoble Alpes, Grenoble INP, IRIG-Spintec, Grenoble, 38000, France
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Guillet T, Galceran R, Sierra JF, Belarre FJ, Ballesteros B, Costache MV, Dosenovic D, Okuno H, Marty A, Jamet M, Bonell F, Valenzuela SO. Spin-Orbit Torques and Magnetization Switching in (Bi,Sb) 2Te 3/Fe 3GeTe 2 Heterostructures Grown by Molecular Beam Epitaxy. Nano Lett 2024; 24:822-828. [PMID: 38263950 DOI: 10.1021/acs.nanolett.3c03291] [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: 01/25/2024]
Abstract
Topological insulators (TIs) hold promise for manipulating the magnetization of a ferromagnet (FM) through the spin-orbit torque (SOT) mechanism. However, integrating TIs with conventional FMs often leads to significant device-to-device variations and a broad distribution of SOT magnitudes. In this work, we present a scalable approach to grow a full van der Waals FM/TI heterostructure by molecular beam epitaxy, combining the charge-compensated TI (Bi,Sb)2Te3 with 2D FM Fe3GeTe2 (FGT). Harmonic magnetotransport measurements reveal that the SOT efficiency exhibits a non-monotonic temperature dependence and experiences a substantial enhancement with a reduction of the FGT thickness to 2 monolayers. Our study further demonstrates that the magnetization of ultrathin FGT films can be switched with a current density of Jc ∼ 1010 A/m2, with minimal device-to-device variations compared to previous investigations involving traditional FMs.
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Affiliation(s)
- Thomas Guillet
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Campus UAB, Bellaterra, 08193 Barcelona, Spain
| | - Regina Galceran
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Campus UAB, Bellaterra, 08193 Barcelona, Spain
| | - Juan F Sierra
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Campus UAB, Bellaterra, 08193 Barcelona, Spain
| | - Francisco J Belarre
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Campus UAB, Bellaterra, 08193 Barcelona, Spain
| | - Belén Ballesteros
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Campus UAB, Bellaterra, 08193 Barcelona, Spain
| | - Marius V Costache
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Campus UAB, Bellaterra, 08193 Barcelona, Spain
| | | | - Hanako Okuno
- Univ. Grenoble Alpes, CEA, IRIG-MEM, 38000 Grenoble, France
| | - Alain Marty
- Univ. Grenoble Alpes, CEA, CNRS, Grenoble INP, IRIG-SPINTEC, 38000 Grenoble, France
| | - Matthieu Jamet
- Univ. Grenoble Alpes, CEA, CNRS, Grenoble INP, IRIG-SPINTEC, 38000 Grenoble, France
| | - Frédéric Bonell
- Univ. Grenoble Alpes, CEA, CNRS, Grenoble INP, IRIG-SPINTEC, 38000 Grenoble, France
| | - Sergio O Valenzuela
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Campus UAB, Bellaterra, 08193 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08070 Barcelona, Spain
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3
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Mesple F, Walet NR, Trambly de Laissardière G, Guinea F, Došenović D, Okuno H, Paillet C, Michon A, Chapelier C, Renard VT. Giant Atomic Swirl in Graphene Bilayers with Biaxial Heterostrain. Adv Mater 2023; 35:e2306312. [PMID: 37615204 DOI: 10.1002/adma.202306312] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 08/10/2023] [Indexed: 08/25/2023]
Abstract
The study of moiré engineering started with the advent of van der Waals heterostructures, in which stacking 2D layers with different lattice constants leads to a moiré pattern controlling their electronic properties. The field entered a new era when it was found that adjusting the twist between two graphene layers led to strongly-correlated-electron physics and topological effects associated with atomic relaxation. A twist is now routinely used to adjust the properties of 2D materials. This study investigates a new type of moiré superlattice in bilayer graphene when one layer is biaxially strained with respect to the other-so-called biaxial heterostrain. Scanning tunneling microscopy measurements uncover spiraling electronic states associated with a novel symmetry-breaking atomic reconstruction at small biaxial heterostrain. Atomistic calculations using experimental parameters as inputs reveal that a giant atomic swirl forms around regions of aligned stacking to reduce the mechanical energy of the bilayer. Tight-binding calculations performed on the relaxed structure show that the observed electronic states decorate spiraling domain wall solitons as required by topology. This study establishes biaxial heterostrain as an important parameter to be harnessed for the next step of moiré engineering in van der Waals multilayers.
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Affiliation(s)
- Florie Mesple
- Univ. Grenoble Alpes, CEA, Grenoble INP, IRIG, PHELIQS, Grenoble, 38000, France
| | - Niels R Walet
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PY, UK
| | - Guy Trambly de Laissardière
- Laboratoire de Physique Théorique et Modélisation (UMR 8089), CY Cergy Paris Université, CNRS, Cergy-Pontoise, 95302, France
| | - Francisco Guinea
- Imdea Nanoscience, Faraday 9, Madrid, 28015, Spain
- Donostia International Physics Center, Paseo Manuel de Lardizábal 4, San Sebastián, 20018, Spain
| | | | - Hanako Okuno
- University Grenoble Alpes, CEA, IRIG-MEM, Grenoble, 38054, France
| | - Colin Paillet
- Université Côte d'Azur, CNRS, CRHEA, Rue Bernard Grégory, Valbonne, 06560, France
| | - Adrien Michon
- Université Côte d'Azur, CNRS, CRHEA, Rue Bernard Grégory, Valbonne, 06560, France
| | - Claude Chapelier
- Univ. Grenoble Alpes, CEA, Grenoble INP, IRIG, PHELIQS, Grenoble, 38000, France
| | - Vincent T Renard
- Univ. Grenoble Alpes, CEA, Grenoble INP, IRIG, PHELIQS, Grenoble, 38000, France
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4
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Duong TM, Sharma K, Agnese F, Rouviere JL, Okuno H, Pouget S, Reiss P, Ling WL. Practice of electron microscopy on nanoparticles sensitive to radiation damage: CsPbBr 3 nanocrystals as a case study. Front Chem 2022; 10:1058620. [PMID: 36605121 PMCID: PMC9808052 DOI: 10.3389/fchem.2022.1058620] [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: 09/30/2022] [Accepted: 12/02/2022] [Indexed: 12/24/2022] Open
Abstract
In-depth and reliable characterization of advanced nanoparticles is crucial for revealing the origin of their unique features and for designing novel functional materials with tailored properties. Due to their small size, characterization beyond nanometric resolution, notably, by transmission electron microscopy (TEM) and associated techniques, is essential to provide meaningful information. Nevertheless, nanoparticles, especially those containing volatile elements or organic components, are sensitive to radiation damage. Here, using CsPbBr3 perovskite nanocrystals as an example, strategies to preserve the native structure of radiation-sensitive nanocrystals in high-resolution electron microscopy studies are presented. Atomic-resolution images obtained using graphene support films allow for a clear comparison with simulation results, showing that most CsPbBr3 nanocrystals are orthorhombic. Low-dose TEM reveals faceted nanocrystals with no in situ formed Pb crystallites, a feature observed in previous TEM studies that has been attributed to radiation damage. Cryo-electron microscopy further delays observable effects of radiation damage. Powder electron diffraction with a hybrid pixel direct electron detector confirms the domination of orthorhombic crystals. These results emphasize the importance of optimizing TEM grid preparation and of exploiting data collection strategies that impart minimum electron dose for revealing the true structure of radiation-sensitive nanocrystals.
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Affiliation(s)
- Tuan M. Duong
- Université Grenoble Alpes, CEA, CNRS, IRIG, SyMMES, STEP, Grenoble, France
| | - Kshipra Sharma
- Université Grenoble Alpes, CEA, IRIG, MEM, LEMMA, Grenoble, France
| | - Fabio Agnese
- Université Grenoble Alpes, CEA, IRIG, MEM, LEMMA, Grenoble, France
| | | | - Hanako Okuno
- Université Grenoble Alpes, CEA, IRIG, MEM, LEMMA, Grenoble, France
| | - Stéphanie Pouget
- Université Grenoble Alpes, CEA, IRIG, MEM, SGX, Grenoble, France
| | - Peter Reiss
- Université Grenoble Alpes, CEA, CNRS, IRIG, SyMMES, STEP, Grenoble, France,*Correspondence: Peter Reiss, ; Wai Li Ling,
| | - Wai Li Ling
- Université Grenoble Alpes, CEA, CNRS, IBS, Grenoble, France,*Correspondence: Peter Reiss, ; Wai Li Ling,
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5
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da Silva BC, Sadre Momtaz Z, Monroy E, Okuno H, Rouviere JL, Cooper D, Den Hertog MI. Assessment of Active Dopants and p-n Junction Abruptness Using In Situ Biased 4D-STEM. Nano Lett 2022; 22:9544-9550. [PMID: 36442685 DOI: 10.1021/acs.nanolett.2c03684] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
A key issue in the development of high-performance semiconductor devices is the ability to properly measure active dopants at the nanometer scale. In a p-n junction, the abruptness of the dopant profile around the metallurgical junction directly influences the electric field. Here, a contacted nominally symmetric and highly doped (NA = ND = 9 × 1018 cm-3) silicon p-n specimen is studied through in situ biased four-dimensional scanning transmission electron microscopy (4D-STEM). Measurements of electric field, built-in voltage, depletion region width, and charge density are combined with analytical equations and finite-element simulations in order to evaluate the quality of the junction interface. It is shown that all the junction parameters measured are compatible with a linearly graded junction. This hypothesis is also consistent with the evolution of the electric field with bias as well as off-axis electron holography data. These results demonstrate that in situ biased 4D-STEM can allow a better understanding of the electrostatics of semiconductor p-n junctions with nm-scale resolution.
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Affiliation(s)
| | | | - Eva Monroy
- Université Grenoble Alpes, CEA, Grenoble INP, IRIG, PHELIQS, F-38000Grenoble, France
| | - Hanako Okuno
- Université Grenoble Alpes, CEA, IRIG, MEM, LEMMA, F-38000Grenoble, France
| | - Jean-Luc Rouviere
- Université Grenoble Alpes, CEA, IRIG, MEM, LEMMA, F-38000Grenoble, France
| | - David Cooper
- Université Grenoble Alpes, CEA-LETI, F-38000Grenoble, France
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6
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Yamasaki K, Yanagi O, Sunada Y, Hatta K, Shigesada R, Sumino M, Yamaguchi T, Islam MA, Tamura N, Okuno H, Namba S. Discharge characteristics of steady-state high-density plasma source based on cascade arc discharge with hollow cathode. Rev Sci Instrum 2022; 93:053502. [PMID: 35649751 DOI: 10.1063/5.0076388] [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: 10/24/2021] [Accepted: 04/18/2022] [Indexed: 06/15/2023]
Abstract
We developed a steady-state high-density plasma source by applying a hollow cathode to a cascade arc discharge device. The hollow cathode is made of a thermionic material (LaB6) to facilitate plasma production inside it. The cascade arc discharge device with the hollow cathode produced a stationary plasma with an electron density of about 1016 cm-3. It was found that the plasma source produces a strong pressure gradient between the gas feed and the vacuum chamber. The plasma source separated the atmospheric pressure (100 kPa) and a vacuum (100 Pa) when the discharge was performed with an argon gas flow rate of 5.0 l/min and a discharge current of 40 A. An analysis of the pressure gradient along the plasma source showed that the pressure difference between the gas feed and the vacuum chamber can be well described by the Hagen-Poiseuille flow equation, indicating that the viscosity of the neutral gas is the dominant factor for producing this pressure gradient. A potential profile analysis suggested that the plasma was mainly heated within cylindrical channels whose inner diameter was 3 mm. This feature and the results of the pressure ratio analysis indicated that the temperature, and, thus, viscosity, of the neutral gas increased with the increasing number of intermediate electrodes. The discharge characteristics and shape of the hollow cathode are suitable for plasma window applications.
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Affiliation(s)
- K Yamasaki
- Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1, Kagamiyama, Higashi-hiroshima, Hiroshima 739-8527, Japan
| | - O Yanagi
- Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1, Kagamiyama, Higashi-hiroshima, Hiroshima 739-8527, Japan
| | - Y Sunada
- Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1, Kagamiyama, Higashi-hiroshima, Hiroshima 739-8527, Japan
| | - K Hatta
- Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1, Kagamiyama, Higashi-hiroshima, Hiroshima 739-8527, Japan
| | - R Shigesada
- Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1, Kagamiyama, Higashi-hiroshima, Hiroshima 739-8527, Japan
| | - M Sumino
- Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1, Kagamiyama, Higashi-hiroshima, Hiroshima 739-8527, Japan
| | - T Yamaguchi
- Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1, Kagamiyama, Higashi-hiroshima, Hiroshima 739-8527, Japan
| | - Md Anwarul Islam
- Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1, Kagamiyama, Higashi-hiroshima, Hiroshima 739-8527, Japan
| | - N Tamura
- Deptartment of Helical Plasma Research, National Institute for Fusion Science, 322-6 Oroshi-cyo, Toki, Gifu 509-5292, Japan
| | - H Okuno
- Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198, Japan
| | - S Namba
- Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1, Kagamiyama, Higashi-hiroshima, Hiroshima 739-8527, Japan
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Liu T, Tonnelé C, Zhao S, Rondin L, Elias C, Medina-Lopez D, Okuno H, Narita A, Chassagneux Y, Voisin C, Campidelli S, Beljonne D, Lauret JS. Vibronic effect and influence of aggregation on the photophysics of graphene quantum dots. Nanoscale 2022; 14:3826-3833. [PMID: 35194627 DOI: 10.1039/d1nr08279e] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Graphene quantum dots, atomically precise nanopieces of graphene, are promising nano-objects with potential applications in various domains such as photovoltaics, quantum light emitters and bio-imaging. Despite their interesting prospects, precise reports on their photophysical properties remain scarce. Here, we report on a study of the photophysics of C96H24(C12H25) graphene quantum dots. A combination of optical studies down to the single molecule level with advanced molecular modelling demonstrates the importance of coupling to vibrations in the emission process. Optical fingerprints for H-like aggregates are identified. Our combined experimental-theoretical investigations provide a comprehensive description of the light absorption and emission properties of nanographenes, which not only represents an essential step towards precise control of sample production but also paves the way for new exciting physics focused on twisted graphenoids.
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Affiliation(s)
- Thomas Liu
- Université Paris-Saclay, ENS Paris-Saclay, CentraleSupélec, CNRS, LuMIn, Orsay, France.
| | | | - Shen Zhao
- Université Paris-Saclay, ENS Paris-Saclay, CentraleSupélec, CNRS, LuMIn, Orsay, France.
| | - Loïc Rondin
- Université Paris-Saclay, ENS Paris-Saclay, CentraleSupélec, CNRS, LuMIn, Orsay, France.
| | - Christine Elias
- Université Paris-Saclay, ENS Paris-Saclay, CentraleSupélec, CNRS, LuMIn, Orsay, France.
| | - Daniel Medina-Lopez
- Université Paris-Saclay, CEA, CNRS, NIMBE, LICSEN, 91191, Gif-sur-Yvette, France
| | - Hanako Okuno
- University Grenoble Alpes, CEA INAC-MEM, F-38000 Grenoble, France
| | - Akimitsu Narita
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Yannick Chassagneux
- LPENS, PSL, CNRS, Université de Paris, Sorbonne Université, 75005 Paris, France
| | - Christophe Voisin
- LPENS, PSL, CNRS, Université de Paris, Sorbonne Université, 75005 Paris, France
| | - Stéphane Campidelli
- Université Paris-Saclay, CEA, CNRS, NIMBE, LICSEN, 91191, Gif-sur-Yvette, France
| | | | - Jean-Sébastien Lauret
- Université Paris-Saclay, ENS Paris-Saclay, CentraleSupélec, CNRS, LuMIn, Orsay, France.
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8
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Ghedjatti A, Coutard N, Calvillo L, Granozzi G, Reuillard B, Artero V, Guetaz L, Lyonnard S, Okuno H, Chenevier P. How do H 2 oxidation molecular catalysts assemble onto carbon nanotube electrodes? A crosstalk between electrochemical and multi-physical characterization techniques. Chem Sci 2021; 12:15916-15927. [PMID: 35024115 PMCID: PMC8672770 DOI: 10.1039/d1sc05168g] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 11/19/2021] [Indexed: 01/27/2023] Open
Abstract
Molecular catalysts show powerful catalytic efficiency and unsurpassed selectivity in many reactions of interest. As their implementation in electrocatalytic devices requires their immobilization onto a conductive support, controlling the grafting chemistry and its impact on their distribution at the surface of this support within the catalytic layer is key to enhancing and stabilizing the current they produce. This study focuses on molecular bioinspired nickel catalysts for hydrogen oxidation, bound to carbon nanotubes, a conductive support with high specific area. We couple advanced analysis by transmission electron microscopy (TEM), for direct imaging of the catalyst layer on individual nanotubes, and small angle neutron scattering (SANS), for indirect observation of structural features in a relevant aqueous medium. Low-dose TEM imaging shows a homogeneous, mobile coverage of catalysts, likely as a monolayer coating the nanotubes, while SANS unveils a regular nanostructure in the catalyst distribution on the surface with agglomerates that could be imaged by TEM upon aging. Together, electrochemistry, TEM and SANS analyses allowed drawing an unprecedented and intriguing picture with molecular catalysts evenly distributed at the nanoscale in two different populations required for optimal catalytic performance. How do efficient hydrogen-oxidation molecular electrocatalysts connect onto their carbon nanotube conductive support? A coupled neutron scattering SANS and STEM electron microscopy study to observe soft active matter organizing on 3D nanosurfaces.![]()
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Affiliation(s)
- Ahmed Ghedjatti
- Univ. Grenoble Alpes, CNRS, CEA, IRIG, Laboratoire de Chimie et Biologie des Métaux 38000 Grenoble France.,Univ. Grenoble Alpes, CEA, IRIG, MEM, LEMMA 38000 Grenoble France.,Univ. Grenoble Alpes, CEA, CNRS, IRIG, SYMMES 38000 Grenoble France
| | - Nathan Coutard
- Univ. Grenoble Alpes, CNRS, CEA, IRIG, Laboratoire de Chimie et Biologie des Métaux 38000 Grenoble France
| | - Laura Calvillo
- Department of Chemical Sciences, University of Padova Via F. Marzolo 1 Padova 35131 Italy
| | - Gaetano Granozzi
- Department of Chemical Sciences, University of Padova Via F. Marzolo 1 Padova 35131 Italy
| | - Bertrand Reuillard
- Univ. Grenoble Alpes, CNRS, CEA, IRIG, Laboratoire de Chimie et Biologie des Métaux 38000 Grenoble France
| | - Vincent Artero
- Univ. Grenoble Alpes, CNRS, CEA, IRIG, Laboratoire de Chimie et Biologie des Métaux 38000 Grenoble France
| | - Laure Guetaz
- Univ. Grenoble Alpes, CEA, LITEN, DTNM 38000 Grenoble France
| | | | - Hanako Okuno
- Univ. Grenoble Alpes, CEA, IRIG, MEM, LEMMA 38000 Grenoble France
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Valleix R, Zhang Q, Boyer D, Boutinaud P, Chadeyron G, Feng Y, Okuno H, Réveret F, Hintze-Bruening H, Leroux F. A First Wide-Open LDH Structure Hosting InP/ZnS QDs: A New Route Toward Efficient and Photostable Red-Emitting Phosphor. Adv Mater 2021; 33:e2103411. [PMID: 34339063 DOI: 10.1002/adma.202103411] [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: 05/05/2021] [Indexed: 06/13/2023]
Abstract
The architecture of Zn-Al layered double hydroxides (LDHs), organo-modified with bola-amphiphiles molecules, is matching its interlayer space to the size of narrow-band red-emitting InP/ZnS core-shell quantum dots (QDs) to form original high-performance functional organic-inorganic QD-bola-LDH hybrids. The success of size-matching interlayer space (SMIS) approach is confirmed by X-ray diffraction, small angle X-ray scattering (SAXS), TEM, STEM-HAADF, and photoluminescence investigations. The QD-Bola-LDH hybrid exhibits a photoluminescence quantum yield three times higher than that of pristine InP/ZnS QDs and provides an easy dispersion into silicone-based resins, what makes the SMIS approach a change of paradigm compared to intercalation chemistry using common host structures. Moreover, this novel hybrid presents low QD-QD energy transfer comparable to that obtained for QDs in suspension. Composite silicone films incorporating InP/ZnS (0.27 wt%) QD-bola-LDH hybrids further show remarkable improved photostability relative to pristine QDs. An LED overlay consisting of a blue LED chip and silicone films loaded with QD-bola-LDH hybrids and YAG:Ce phosphors exhibits a color rendering index close to 94.
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Affiliation(s)
- Rodolphe Valleix
- Université Clermont Auvergne, Clermont Auvergne INP, CNRS, ICCF, Clermont-Ferrand, F-63000, France
| | - Qian Zhang
- Université Clermont Auvergne, Clermont Auvergne INP, CNRS, ICCF, Clermont-Ferrand, F-63000, France
- State Key Laboratory of Chemical Resource Engineering, Beijing Engineering Center for Hierarchical Catalysts, University of Chemical Technology, No. 15 Beisanhuan East Road, Beijing, 100029, China
| | - Damien Boyer
- Université Clermont Auvergne, Clermont Auvergne INP, CNRS, ICCF, Clermont-Ferrand, F-63000, France
| | - Philippe Boutinaud
- Université Clermont Auvergne, Clermont Auvergne INP, CNRS, ICCF, Clermont-Ferrand, F-63000, France
| | - Geneviève Chadeyron
- Université Clermont Auvergne, Clermont Auvergne INP, CNRS, ICCF, Clermont-Ferrand, F-63000, France
| | - Yongjun Feng
- State Key Laboratory of Chemical Resource Engineering, Beijing Engineering Center for Hierarchical Catalysts, University of Chemical Technology, No. 15 Beisanhuan East Road, Beijing, 100029, China
| | - Hanako Okuno
- Beijing Université Grenoble Alpes, CEA, IRIG-MEM, Grenoble, 38000, France
| | - François Réveret
- Université Clermont Auvergne, Clermont Auvergne INP, CNRS, Institut Pascal, Clermont-Ferrand, F-63000, France
| | | | - Fabrice Leroux
- Université Clermont Auvergne, Clermont Auvergne INP, CNRS, ICCF, Clermont-Ferrand, F-63000, France
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10
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Ahn JK, Beckford B, Campbell M, Chen SH, Comfort J, Dona K, Farrington MS, Hanai K, Hara N, Haraguchi H, Hsiung YB, Hutcheson M, Inagaki T, Isoe M, Kamiji I, Kato T, Kim EJ, Kim JL, Kim HM, Komatsubara TK, Kotera K, Lee SK, Lee JW, Lim GY, Lin QS, Lin C, Luo Y, Mari T, Masuda T, Matsumura T, Mcfarland D, McNeal N, Miyazaki K, Murayama R, Nakagiri K, Nanjo H, Nishimiya H, Noichi Y, Nomura T, Nunes T, Ohsugi M, Okuno H, Redeker JC, Sanchez J, Sasaki M, Sasao N, Sato T, Sato K, Sato Y, Shimizu N, Shimogawa T, Shinkawa T, Shinohara S, Shiomi K, Shiraishi R, Su S, Sugiyama Y, Suzuki S, Tajima Y, Taylor M, Tecchio M, Togawa M, Toyoda T, Tung YC, Vuong QH, Wah YW, Watanabe H, Yamanaka T, Yoshida HY, Zaidenberg L. Study of the K_{L}→π^{0}νν[over ¯] Decay at the J-PARC KOTO Experiment. Phys Rev Lett 2021; 126:121801. [PMID: 33834796 DOI: 10.1103/physrevlett.126.121801] [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: 12/15/2020] [Accepted: 02/18/2021] [Indexed: 06/12/2023]
Abstract
The rare decay K_{L}→π^{0}νν[over ¯] was studied with the dataset taken at the J-PARC KOTO experiment in 2016, 2017, and 2018. With a single event sensitivity of (7.20±0.05_{stat}±0.66_{syst})×10^{-10}, three candidate events were observed in the signal region. After unveiling them, contaminations from K^{±} and scattered K_{L} decays were studied, and the total number of background events was estimated to be 1.22±0.26. We conclude that the number of observed events is statistically consistent with the background expectation. For this dataset, we set an upper limit of 4.9×10^{-9} on the branching fraction of K_{L}→π^{0}νν[over ¯] at the 90% confidence level.
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Affiliation(s)
- J K Ahn
- Department of Physics, Korea University, Seoul 02841, Republic of Korea
| | - B Beckford
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - M Campbell
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - S H Chen
- Department of Physics, National Taiwan University, Taipei, Taiwan 10617, Republic of China
| | - J Comfort
- Department of Physics, Arizona State University, Tempe, Arizona 85287, USA
| | - K Dona
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - M S Farrington
- Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - K Hanai
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - N Hara
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - H Haraguchi
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Y B Hsiung
- Department of Physics, National Taiwan University, Taipei, Taiwan 10617, Republic of China
| | - M Hutcheson
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - T Inagaki
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - M Isoe
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - I Kamiji
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - T Kato
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - E J Kim
- Division of Science Education, Jeonbuk National University, Jeonju 54896, Republic of Korea
| | - J L Kim
- Division of Science Education, Jeonbuk National University, Jeonju 54896, Republic of Korea
| | - H M Kim
- Division of Science Education, Jeonbuk National University, Jeonju 54896, Republic of Korea
| | - T K Komatsubara
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
- J-PARC Center, Tokai, Ibaraki 319-1195, Japan
| | - K Kotera
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - S K Lee
- Division of Science Education, Jeonbuk National University, Jeonju 54896, Republic of Korea
| | - J W Lee
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - G Y Lim
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
- J-PARC Center, Tokai, Ibaraki 319-1195, Japan
| | - Q S Lin
- Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - C Lin
- Department of Physics, National Taiwan University, Taipei, Taiwan 10617, Republic of China
| | - Y Luo
- Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - T Mari
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - T Masuda
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
| | - T Matsumura
- Department of Applied Physics, National Defense Academy, Kanagawa 239-8686, Japan
| | - D Mcfarland
- Department of Physics, Arizona State University, Tempe, Arizona 85287, USA
| | - N McNeal
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - K Miyazaki
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - R Murayama
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - K Nakagiri
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - H Nanjo
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - H Nishimiya
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Y Noichi
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - T Nomura
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
- J-PARC Center, Tokai, Ibaraki 319-1195, Japan
| | - T Nunes
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - M Ohsugi
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - H Okuno
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - J C Redeker
- Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - J Sanchez
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - M Sasaki
- Department of Physics, Yamagata University, Yamagata 990-8560, Japan
| | - N Sasao
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
| | - T Sato
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - K Sato
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Y Sato
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - N Shimizu
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - T Shimogawa
- Department of Physics, Saga University, Saga 840-8502, Japan
| | - T Shinkawa
- Department of Applied Physics, National Defense Academy, Kanagawa 239-8686, Japan
| | - S Shinohara
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - K Shiomi
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
- J-PARC Center, Tokai, Ibaraki 319-1195, Japan
| | - R Shiraishi
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - S Su
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Y Sugiyama
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - S Suzuki
- Department of Physics, Saga University, Saga 840-8502, Japan
| | - Y Tajima
- Department of Physics, Yamagata University, Yamagata 990-8560, Japan
| | - M Taylor
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - M Tecchio
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - M Togawa
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - T Toyoda
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Y-C Tung
- Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - Q H Vuong
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Y W Wah
- Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - H Watanabe
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
- J-PARC Center, Tokai, Ibaraki 319-1195, Japan
| | - T Yamanaka
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - H Y Yoshida
- Department of Physics, Yamagata University, Yamagata 990-8560, Japan
| | - L Zaidenberg
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
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11
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Ghosh S, Komori T, Hallal A, Peña Garcia J, Gushi T, Hirose T, Mitarai H, Okuno H, Vogel J, Chshiev M, Attané JP, Vila L, Suemasu T, Pizzini S. Current-Driven Domain Wall Dynamics in Ferrimagnetic Nickel-Doped Mn 4N Films: Very Large Domain Wall Velocities and Reversal of Motion Direction across the Magnetic Compensation Point. Nano Lett 2021; 21:2580-2587. [PMID: 33705154 DOI: 10.1021/acs.nanolett.1c00125] [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: 06/12/2023]
Abstract
Spin-transfer torque (STT) and spin-orbit torque (SOT) are spintronic phenomena allowing magnetization manipulation using electrical currents. Beyond their fundamental interest, they allow developing new classes of magnetic memories and logic devices, in particular based on domain wall (DW) motion. In this work, we report the study of STT-driven DW motion in ferrimagnetic manganese nickel nitride (Mn4-xNixN) films, in which magnetization and angular momentum compensation can be obtained by the fine adjustment of the Ni content. Large domain wall velocities, approaching 3000 m/s, are measured for Ni compositions close to the angular momentum compensation point. The reversal of the DW motion direction, observed when the compensation composition is crossed, is related to the change of direction of the angular momentum with respect to that of the spin polarization. This is confirmed by the results of ab initio band structure calculations.
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Affiliation(s)
- Sambit Ghosh
- Université Grenoble Alpes, CEA, CNRS, Grenoble INP, IRIG-Spintec, 38054 Grenoble, France
- Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan
| | - Taro Komori
- Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan
| | - Ali Hallal
- Université Grenoble Alpes, CEA, CNRS, Grenoble INP, IRIG-Spintec, 38054 Grenoble, France
| | - Jose Peña Garcia
- Université Grenoble Alpes, CNRS, Institut Néel, 38042 Grenoble, France
| | - Toshiki Gushi
- Université Grenoble Alpes, CEA, CNRS, Grenoble INP, IRIG-Spintec, 38054 Grenoble, France
- Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan
| | - Taku Hirose
- Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan
| | - Haruka Mitarai
- Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan
| | - Hanako Okuno
- Université Grenoble Alpes, CEA, IRIG-MEM, 38000 Grenoble, France
| | - Jan Vogel
- Université Grenoble Alpes, CNRS, Institut Néel, 38042 Grenoble, France
| | - Mairbek Chshiev
- Université Grenoble Alpes, CEA, CNRS, Grenoble INP, IRIG-Spintec, 38054 Grenoble, France
- Institut Universitaire de France, 75231, Paris, France
| | - Jean-Philippe Attané
- Université Grenoble Alpes, CEA, CNRS, Grenoble INP, IRIG-Spintec, 38054 Grenoble, France
| | - Laurent Vila
- Université Grenoble Alpes, CEA, CNRS, Grenoble INP, IRIG-Spintec, 38054 Grenoble, France
| | - Takashi Suemasu
- Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan
| | - Stefania Pizzini
- Université Grenoble Alpes, CNRS, Institut Néel, 38042 Grenoble, France
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12
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Mallet P, Chiapello F, Okuno H, Boukari H, Jamet M, Veuillen JY. Bound Hole States Associated to Individual Vanadium Atoms Incorporated into Monolayer WSe_{2}. Phys Rev Lett 2020; 125:036802. [PMID: 32745415 DOI: 10.1103/physrevlett.125.036802] [Citation(s) in RCA: 3] [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: 12/19/2019] [Accepted: 06/09/2020] [Indexed: 06/11/2023]
Abstract
Doping a two-dimensional semiconductor with magnetic atoms is a possible route to induce magnetism in the material. We report on the atomic structure and electronic properties of monolayer WSe_{2} intentionally doped with vanadium atoms by means of scanning transmission electron microscopy and scanning tunneling microscopy and spectroscopy. Most of the V atoms incorporate at W sites. These V_{W} dopants are negatively charged, which induces a localized bound state located 140 meV above the valence band maximum. The overlap of the electronic potential of two charged V_{W} dopants generates additional in-gap states. Eventually, the negative charge may suppress the magnetic moment on the V_{W} dopants.
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Affiliation(s)
- Pierre Mallet
- Université Grenoble Alpes, Institut Neel, F-38042 Grenoble, France
- CNRS, Institut Neel, F-38042 Grenoble, France
| | - Florian Chiapello
- Université Grenoble Alpes, Institut Neel, F-38042 Grenoble, France
- CNRS, Institut Neel, F-38042 Grenoble, France
| | - Hanako Okuno
- Université Grenoble Alpes, CEA, IRIG-MEM, 38000 Grenoble, France
| | - Hervé Boukari
- Université Grenoble Alpes, Institut Neel, F-38042 Grenoble, France
- CNRS, Institut Neel, F-38042 Grenoble, France
| | - Matthieu Jamet
- Université Grenoble Alpes, CEA, CNRS, Grenoble INP, IRIG-SPINTEC, 38000 Grenoble, France
| | - Jean-Yves Veuillen
- Université Grenoble Alpes, Institut Neel, F-38042 Grenoble, France
- CNRS, Institut Neel, F-38042 Grenoble, France
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13
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Ikoma N, Miyake Y, Takahashi M, Okuno H, Namba S, Takahashi K, Sasaki T, Kikuchi T. Characteristics of plasma window with various channel diameters for accelerator applications. Rev Sci Instrum 2020; 91:053503. [PMID: 32486757 DOI: 10.1063/1.5140709] [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: 11/30/2019] [Accepted: 04/29/2020] [Indexed: 06/11/2023]
Abstract
Plasma window is a feasible device as an atmosphere-vacuum interface, which can withstand energetic particle beams. It is, however, essential to enlarge the diameter to several tens of millimeters for actual beam passing in the accelerator applications. The pressure separation performance and discharge voltage V current I characteristics should be investigated in detail to design the plasma window for each purpose. Therefore, a cascade arc discharge device with a diameter of up to 20 mm was developed, and its characteristics as a function of diameter were examined. As a result, with an increase in the channel diameter, the discharge pressure that was achieved decreased, whose values were smaller compared with the values by the prediction formula, assuming the viscous gas flow with a constant plasma temperature. It showed that the bulk plasma temperature for the larger discharge channel was low because of the low-current density over the channel. Furthermore, the transition of the V-I slope was observed with an increase in the diameter.
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Affiliation(s)
- N Ikoma
- Nishina Center for Accelerator-Based Science, RIKEN, Saitama 351-0198, Japan
| | - Y Miyake
- Nishina Center for Accelerator-Based Science, RIKEN, Saitama 351-0198, Japan
| | - M Takahashi
- Nishina Center for Accelerator-Based Science, RIKEN, Saitama 351-0198, Japan
| | - H Okuno
- Nishina Center for Accelerator-Based Science, RIKEN, Saitama 351-0198, Japan
| | - S Namba
- Graduate School of Engineering, Hiroshima University, Hiroshima 739-8527, Japan
| | - K Takahashi
- Graduate School of Engineering, Nagaoka University of Technology, Niigata 940-2188, Japan
| | - T Sasaki
- Graduate School of Engineering, Nagaoka University of Technology, Niigata 940-2188, Japan
| | - T Kikuchi
- Graduate School of Engineering, Nagaoka University of Technology, Niigata 940-2188, Japan
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14
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Vergnaud C, Dau MT, Grévin B, Licitra C, Marty A, Okuno H, Jamet M. New approach for the molecular beam epitaxy growth of scalable WSe 2 monolayers. Nanotechnology 2020; 31:255602. [PMID: 32187582 DOI: 10.1088/1361-6528/ab80fe] [Citation(s) in RCA: 5] [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] [Indexed: 06/10/2023]
Abstract
The search for high-quality transition metal dichalcogenides mono- and multi-layers grown on large areas is still a very active field of investigation. Here, we use molecular beam epitaxy to grow WSe2 on 15 × 15 mm large mica in the van der Waals regime. By screening one-step growth conditions, we find that very high temperature (>900 °C) and very low deposition rate (<0.15 Å min-1) are necessary to obtain high quality WSe2 films. The domain size can be as large as 1 µm and the in-plane rotational misorientation of 1.25°. The WSe2 monolayer is also robust against air exposure, can be easily transferred over 1 cm2 on SiN/SiO2 and exhibits strong photoluminescence signal. Moreover, by combining grazing incidence x-ray diffraction and transmission electron microscopy, we could detect the presence of few misoriented grains. A two-dimensional model based on atomic coincidences between the WSe2 and mica crystals allows us to explain the formation of these misoriented grains and gives insight to achieve highly crystalline WSe2.
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Affiliation(s)
- Céline Vergnaud
- Univ. Grenoble Alpes, CEA, CNRS, Grenoble INP, IRIG-Spintec, 38000 Grenoble, France
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15
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Gruart M, Feldberg N, Gayral B, Bougerol C, Pouget S, Bellet-Amalric E, Garro N, Cros A, Okuno H, Daudin B. Impact of kinetics on the growth of GaN on graphene by plasma-assisted molecular beam epitaxy. Nanotechnology 2020; 31:115602. [PMID: 31774414 DOI: 10.1088/1361-6528/ab5c15] [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] [Indexed: 06/10/2023]
Abstract
The growth of GaN on graphene by molecular beam epitaxy was investigated. The most stable epitaxial relationship, i.e. [00.1]-oriented grains, is obtained at high temperature and N-rich conditions, which match those for nanowire growth. Alternatively, at moderate temperature and Ga-rich conditions, several metastable orientations are observed at the nucleation stage, which evolve preferentially towards [00.1]-oriented grains. The dependence of the nucleation regime on growth conditions was assigned to Ga adatom kinetics. This statement is consistent with the calculated graphene/GaN in-plane lattice coincidence and supported by a combination of transmission electron microscopy, x-ray diffraction, photoluminescence, and Raman spectroscopy experiments.
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Affiliation(s)
- M Gruart
- Univ. Grenoble-Alpes, CEA-IRIG, PHELIQS, 17 av. des Martyrs, F-38000, Grenoble, France
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16
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Journot T, Okuno H, Mollard N, Michon A, Dagher R, Gergaud P, Dijon J, Kolobov AV, Hyot B. Remote epitaxy using graphene enables growth of stress-free GaN. Nanotechnology 2019; 30:505603. [PMID: 31530744 DOI: 10.1088/1361-6528/ab4501] [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] [Indexed: 06/10/2023]
Abstract
The properties of group III-Nitrides (III-N) such as a large direct bandgap, high melting point, and high breakdown voltage make them very attractive for optoelectronic applications. However, conventional epitaxy on SiC and sapphire substrates results in strained and defective films with consequently poor device performance. In this work, by studying the nucleation of GaN on graphene/SiC by MOVPE, we unambiguously demonstrate the possibility of remote van der Waals epitaxy. By choosing the appropriate growth conditions, GaN crystals can grow either in-plane misoriented or fully epitaxial to the substrate. The adhesion forces across the GaN and graphene interface are very weak and the micron-scale nuclei can be easily moved around. The combined use of x-ray diffraction and transmission electron microscopy demonstrate the growth of stress-free and dislocation-free crystals. The high quality of the crystals was further confirmed by photoluminescence measurements. First principles calculations additionally highlighted the importance of the polarity of the underlying substrate. This work lays the first brick towards the synthesis of high quality III-N thin films grown via van der Waals epitaxy.
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Affiliation(s)
- T Journot
- Univ. Grenoble Alpes, F-38000 Grenoble, France. CEA, LETI, MINATEC campus, F-38000 Grenoble, France
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17
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Gushi T, Jovičević Klug M, Peña Garcia J, Ghosh S, Attané JP, Okuno H, Fruchart O, Vogel J, Suemasu T, Pizzini S, Vila L. Large Current Driven Domain Wall Mobility and Gate Tuning of Coercivity in Ferrimagnetic Mn 4N Thin Films. Nano Lett 2019; 19:8716-8723. [PMID: 31664840 DOI: 10.1021/acs.nanolett.9b03416] [Citation(s) in RCA: 2] [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] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Spintronics, which is the basis of a low-power, beyond-CMOS technology for computational and memory devices, remains up to now entirely based on critical materials such as Co, heavy metals and rare-earths. Here, we show that Mn4N, a rare-earth free ferrimagnet made of abundant elements, is an exciting candidate for the development of sustainable spintronics devices. Mn4N thin films grown epitaxially on SrTiO3 substrates possess remarkable properties, such as a perpendicular magnetization, a very high extraordinary Hall angle (2%) and smooth domain walls at the millimeter scale. Moreover, domain walls can be moved at record speeds by spin-polarized currents, in absence of spin-orbit torques. This can be explained by the large efficiency of the adiabatic spin transfer torque, due to the conjunction of a reduced magnetization and a large spin polarization. Finally, we show that the application of gate voltages through the SrTiO3 substrates allows modulating the Mn4N coercive field with a large efficiency.
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Affiliation(s)
- Toshiki Gushi
- Institute of Applied Physics, Graduate School of Pure and Applied Sciences , University of Tsukuba , Tsukuba , Ibaraki 305-8573 , Japan
- Université Grenoble Alpes , CEA, CNRS, Grenoble INP, SPINTEC , F-38000 Grenoble , France
| | | | - Jose Peña Garcia
- Université Grenoble Alpes , CNRS, Institut Neél , F-38042 Grenoble , France
| | - Sambit Ghosh
- Université Grenoble Alpes , CEA, CNRS, Grenoble INP, SPINTEC , F-38000 Grenoble , France
| | - Jean-Philippe Attané
- Université Grenoble Alpes , CEA, CNRS, Grenoble INP, SPINTEC , F-38000 Grenoble , France
| | - Hanako Okuno
- Université Grenoble Alpes , CEA, IRIG, MEM , F-38000 Grenoble , France
| | - Olivier Fruchart
- Université Grenoble Alpes , CEA, CNRS, Grenoble INP, SPINTEC , F-38000 Grenoble , France
| | - Jan Vogel
- Université Grenoble Alpes , CNRS, Institut Neél , F-38042 Grenoble , France
| | - Takashi Suemasu
- Institute of Applied Physics, Graduate School of Pure and Applied Sciences , University of Tsukuba , Tsukuba , Ibaraki 305-8573 , Japan
| | - Stefania Pizzini
- Université Grenoble Alpes , CNRS, Institut Neél , F-38042 Grenoble , France
| | - Laurent Vila
- Université Grenoble Alpes , CEA, CNRS, Grenoble INP, SPINTEC , F-38000 Grenoble , France
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18
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Vaz DC, Noël P, Johansson A, Göbel B, Bruno FY, Singh G, McKeown-Walker S, Trier F, Vicente-Arche LM, Sander A, Valencia S, Bruneel P, Vivek M, Gabay M, Bergeal N, Baumberger F, Okuno H, Barthélémy A, Fert A, Vila L, Mertig I, Attané JP, Bibes M. Mapping spin-charge conversion to the band structure in a topological oxide two-dimensional electron gas. Nat Mater 2019; 18:1187-1193. [PMID: 31501554 DOI: 10.1038/s41563-019-0467-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 07/23/2019] [Indexed: 05/23/2023]
Abstract
While spintronics has traditionally relied on ferromagnetic metals as spin generators and detectors, spin-orbitronics exploits the efficient spin-charge interconversion enabled by spin-orbit coupling in non-magnetic systems. Although the Rashba picture of split parabolic bands is often used to interpret such experiments, it fails to explain the largest conversion effects and their relationship with the electronic structure. Here, we demonstrate a very large spin-to-charge conversion effect in an interface-engineered, high-carrier-density SrTiO3 two-dimensional electron gas and map its gate dependence on the band structure. We show that the conversion process is amplified by enhanced Rashba-like splitting due to orbital mixing and in the vicinity of avoided band crossings with topologically non-trivial order. Our results indicate that oxide two-dimensional electron gases are strong candidates for spin-based information readout in new memory and transistor designs. Our results also emphasize the promise of topology as a new ingredient to expand the scope of complex oxides for spintronics.
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Affiliation(s)
- Diogo C Vaz
- Unité Mixte de Physique CNRS/Thales, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France
| | - Paul Noël
- Université Grenoble Alpes, CEA, CNRS, Grenoble INP, IRIG-Spintec, Grenoble, France
| | - Annika Johansson
- Max Planck Institute of Microstructure Physics, Halle, Germany
- Institute of Physics, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Börge Göbel
- Max Planck Institute of Microstructure Physics, Halle, Germany
| | - Flavio Y Bruno
- Department of Quantum Matter Physics, University of Geneva, Geneva, Switzerland
| | - Gyanendra Singh
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL Research University, CNRS, Paris, France
| | | | - Felix Trier
- Unité Mixte de Physique CNRS/Thales, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France
| | - Luis M Vicente-Arche
- Unité Mixte de Physique CNRS/Thales, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France
| | - Anke Sander
- Unité Mixte de Physique CNRS/Thales, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France
| | - Sergio Valencia
- Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany
| | - Pierre Bruneel
- Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, Université Paris-Saclay, Orsay, France
| | - Manali Vivek
- Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, Université Paris-Saclay, Orsay, France
| | - Marc Gabay
- Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, Université Paris-Saclay, Orsay, France
| | - Nicolas Bergeal
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL Research University, CNRS, Paris, France
| | - Felix Baumberger
- Department of Quantum Matter Physics, University of Geneva, Geneva, Switzerland
| | - Hanako Okuno
- Université Grenoble Alpes, CEA, IRIG-MEM, Grenoble, France
| | - Agnès Barthélémy
- Unité Mixte de Physique CNRS/Thales, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France
| | - Albert Fert
- Unité Mixte de Physique CNRS/Thales, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France
| | - Laurent Vila
- Université Grenoble Alpes, CEA, CNRS, Grenoble INP, IRIG-Spintec, Grenoble, France.
| | - Ingrid Mertig
- Max Planck Institute of Microstructure Physics, Halle, Germany
- Institute of Physics, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Jean-Philippe Attané
- Université Grenoble Alpes, CEA, CNRS, Grenoble INP, IRIG-Spintec, Grenoble, France
| | - Manuel Bibes
- Unité Mixte de Physique CNRS/Thales, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France.
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19
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Qin Z, Loh L, Wang J, Xu X, Zhang Q, Haas B, Alvarez C, Okuno H, Yong JZ, Schultz T, Koch N, Dan J, Pennycook SJ, Zeng D, Bosman M, Eda G. Growth of Nb-Doped Monolayer WS 2 by Liquid-Phase Precursor Mixing. ACS Nano 2019; 13:10768-10775. [PMID: 31491079 DOI: 10.1021/acsnano.9b05574] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [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
Controlled substitutional doping of two-dimensional transition-metal dichalcogenides (TMDs) is of fundamental importance for their applications in electronics and optoelectronics. However, achieving p-type conductivity in MoS2 and WS2 is challenging because of their natural tendency to form n-type vacancy defects. Here, we report versatile growth of p-type monolayer WS2 by liquid-phase mixing of a host tungsten source and niobium dopant. We show that crystallites of WS2 with different concentrations of substitutionally doped Nb up to 1014 cm-2 can be grown by reacting solution-deposited precursor film with sulfur vapor at 850 °C, reflecting the good miscibility of the precursors in the liquid phase. Atomic-resolution characterization with aberration-corrected scanning transmission electron microscopy reveals that the Nb concentration along the outer edge region of the flakes increases consistently with the molar concentration of Nb in the precursor solution. We further demonstrate that ambipolar field-effect transistors can be fabricated based on Nb-doped monolayer WS2.
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Affiliation(s)
- Ziyu Qin
- State Key Laboratory of Materials Processing and Die Mould Technology , Huazhong University of Science and Technology (HUST) , No. 1037, Luoyu Road , Wuhan 430074 , China
- Department of Physics , National University of Singapore , 2 Science Drive 3 , Singapore 117551 , Singapore
| | - Leyi Loh
- Department of Physics , National University of Singapore , 2 Science Drive 3 , Singapore 117551 , Singapore
- Department of Materials Science and Engineering , National University of Singapore , 9 Engineering Drive 1 , Singapore 117575 , Singapore
| | - Junyong Wang
- Department of Physics , National University of Singapore , 2 Science Drive 3 , Singapore 117551 , Singapore
| | - Xiaomin Xu
- Institut für Physik & IRIS Adlershof , Humboldt-Universität zu Berlin , Newtonstrasse 15 , 12489 Berlin , Germany
| | - Qi Zhang
- Department of Physics , National University of Singapore , 2 Science Drive 3 , Singapore 117551 , Singapore
| | - Benedikt Haas
- Institut für Physik & IRIS Adlershof , Humboldt-Universität zu Berlin , Newtonstrasse 15 , 12489 Berlin , Germany
| | - Carlos Alvarez
- Univ. Grenoble Alpes , CEA, INAC-MEM , F-38000 Grenoble , France
| | - Hanako Okuno
- Univ. Grenoble Alpes , CEA, INAC-MEM , F-38000 Grenoble , France
| | - Justin Zhou Yong
- Department of Physics , National University of Singapore , 2 Science Drive 3 , Singapore 117551 , Singapore
| | - Thorsten Schultz
- Institut für Physik & IRIS Adlershof , Humboldt-Universität zu Berlin , Newtonstrasse 15 , 12489 Berlin , Germany
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH , Albert-Einstein-Str. 15 , 12489 Berlin , Germany
| | - Norbert Koch
- Institut für Physik & IRIS Adlershof , Humboldt-Universität zu Berlin , Newtonstrasse 15 , 12489 Berlin , Germany
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH , Albert-Einstein-Str. 15 , 12489 Berlin , Germany
| | - Jiadong Dan
- Department of Materials Science and Engineering , National University of Singapore , 9 Engineering Drive 1 , Singapore 117575 , Singapore
| | - Stephen J Pennycook
- Department of Materials Science and Engineering , National University of Singapore , 9 Engineering Drive 1 , Singapore 117575 , Singapore
| | - Dawen Zeng
- State Key Laboratory of Materials Processing and Die Mould Technology , Huazhong University of Science and Technology (HUST) , No. 1037, Luoyu Road , Wuhan 430074 , China
| | - Michel Bosman
- Department of Materials Science and Engineering , National University of Singapore , 9 Engineering Drive 1 , Singapore 117575 , Singapore
| | - Goki Eda
- Department of Physics , National University of Singapore , 2 Science Drive 3 , Singapore 117551 , Singapore
- Department of Chemistry , National University of Singapore , 3 Science Drive 3 , Singapore 117543 , Singapore
- Centre for Advanced 2D Materials , National University of Singapore , 2 Science Drive 2 , Singapore 117542 , Singapore
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20
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Feldberg N, Klymov O, Garro N, Cros A, Mollard N, Okuno H, Gruart M, Daudin B. Spontaneous intercalation of Ga and In bilayers during plasma-assisted molecular beam epitaxy growth of GaN on graphene on SiC. Nanotechnology 2019; 30:375602. [PMID: 31151128 DOI: 10.1088/1361-6528/ab261f] [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] [Indexed: 06/09/2023]
Abstract
The formation of a self-limited metallic bilayer is reported during the growth of GaN by plasma-assisted molecular beam epitaxy on graphene on (0001) SiC. Depending on growth conditions, this layer may consist of either Ga or In, which gets intercalated between graphene and the SiC surface. Diffusion of metal atoms is eased by steps at SiC surface and N plasma induced defects in the graphene layer. Energetically favorable wetting of the (0001) SiC surface by Ga or In is tentatively assigned to the breaking of covalent bonds between (0001) SiC surface and carbon buffer layer. As a consequence, graphene doping and local strain/doping fluctuations decrease. Furthermore, the presence of a metallic layer below GaN opens the way to the development of devices with a spontaneously formed metallic electrode on their back side.
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Affiliation(s)
- Nathaniel Feldberg
- CEA, INAC-PHELIQS 'Nanophysics and semiconductors' group, F-38000 Grenoble, France. CEA, LETI, MINATEC campus, F-38000 Grenoble, France
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21
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Ahn JK, Beckford B, Beechert J, Bryant K, Campbell M, Chen SH, Comfort J, Dona K, Hara N, Haraguchi H, Hsiung YB, Hutcheson M, Inagaki T, Kamiji I, Kawasaki N, Kim EJ, Kim JL, Kim YJ, Ko JW, Komatsubara TK, Kotera K, Kurilin AS, Lee JW, Lim GY, Lin C, Lin Q, Luo Y, Ma J, Maeda Y, Mari T, Masuda T, Matsumura T, Mcfarland D, McNeal N, Micallef J, Miyazaki K, Murayama R, Naito D, Nakagiri K, Nanjo H, Nishimiya H, Nomura T, Ohsugi M, Okuno H, Sasaki M, Sasao N, Sato K, Sato T, Sato Y, Schamis H, Seki S, Shimizu N, Shimogawa T, Shinkawa T, Shinohara S, Shiomi K, Su S, Sugiyama Y, Suzuki S, Tajima Y, Taylor M, Tecchio M, Togawa M, Tung YC, Wah YW, Watanabe H, Woo JK, Yamanaka T, Yoshida HY. Search for K_{L}→π^{0}νν[over ¯] and K_{L}→π^{0}X^{0} Decays at the J-PARC KOTO Experiment. Phys Rev Lett 2019; 122:021802. [PMID: 30720307 DOI: 10.1103/physrevlett.122.021802] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 12/14/2018] [Indexed: 06/09/2023]
Abstract
A search for the rare decay K_{L}→π^{0}νν[over ¯] was performed. With the data collected in 2015, corresponding to 2.2×10^{19} protons on target, a single event sensitivity of (1.30±0.01_{stat}±0.14_{syst})×10^{-9} was achieved and no candidate events were observed. We set an upper limit of 3.0×10^{-9} for the branching fraction of K_{L}→π^{0}νν[over ¯] at the 90% confidence level (C.L.), which improved the previous limit by almost an order of magnitude. An upper limit for K_{L}→π^{0}X^{0} was also set as 2.4×10^{-9} at the 90% C.L., where X^{0} is an invisible boson with a mass of 135 MeV/c^{2}.
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Affiliation(s)
- J K Ahn
- Department of Physics, Korea University, Seoul 02841, Republic of Korea
| | - B Beckford
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - J Beechert
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - K Bryant
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - M Campbell
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - S H Chen
- Department of Physics, National Taiwan University, Taipei, Taiwan 10617, Republic of China
| | - J Comfort
- Department of Physics, Arizona State University, Tempe, Arizona 85287, USA
| | - K Dona
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - N Hara
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - H Haraguchi
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Y B Hsiung
- Department of Physics, National Taiwan University, Taipei, Taiwan 10617, Republic of China
| | - M Hutcheson
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - T Inagaki
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - I Kamiji
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - N Kawasaki
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - E J Kim
- Division of Science Education, Chonbuk National University, Jeonju 54896, Republic of Korea
| | - J L Kim
- Department of Physics, Korea University, Seoul 02841, Republic of Korea
| | - Y J Kim
- Department of Physics, Jeju National University, Jeju 63243, Republic of Korea
| | - J W Ko
- Department of Physics, Jeju National University, Jeju 63243, Republic of Korea
| | - T K Komatsubara
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
- J-PARC Center, Tokai, Ibaraki 319-1195, Japan
| | - K Kotera
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - A S Kurilin
- Laboratory of Nuclear Problems, Joint Institute for Nuclear Researches, Dubna, Moscow region 141980, Russia
| | - J W Lee
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - G Y Lim
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
- J-PARC Center, Tokai, Ibaraki 319-1195, Japan
| | - C Lin
- Department of Physics, National Taiwan University, Taipei, Taiwan 10617, Republic of China
| | - Q Lin
- Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - Y Luo
- Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - J Ma
- Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - Y Maeda
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - T Mari
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - T Masuda
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - T Matsumura
- Department of Applied Physics, National Defense Academy, Kanagawa 239-8686, Japan
| | - D Mcfarland
- Department of Physics, Arizona State University, Tempe, Arizona 85287, USA
| | - N McNeal
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - J Micallef
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - K Miyazaki
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - R Murayama
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - D Naito
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - K Nakagiri
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - H Nanjo
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - H Nishimiya
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - T Nomura
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
- J-PARC Center, Tokai, Ibaraki 319-1195, Japan
| | - M Ohsugi
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - H Okuno
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - M Sasaki
- Department of Physics, Yamagata University, Yamagata 990-8560, Japan
| | - N Sasao
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
| | - K Sato
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - T Sato
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - Y Sato
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - H Schamis
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - S Seki
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - N Shimizu
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - T Shimogawa
- Department of Physics, Saga University, Saga 840-8502, Japan
| | - T Shinkawa
- Department of Applied Physics, National Defense Academy, Kanagawa 239-8686, Japan
| | - S Shinohara
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - K Shiomi
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
- J-PARC Center, Tokai, Ibaraki 319-1195, Japan
| | - S Su
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Y Sugiyama
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - S Suzuki
- Department of Physics, Saga University, Saga 840-8502, Japan
| | - Y Tajima
- Department of Physics, Yamagata University, Yamagata 990-8560, Japan
| | - M Taylor
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - M Tecchio
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - M Togawa
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Y C Tung
- Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - Y W Wah
- Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - H Watanabe
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
- J-PARC Center, Tokai, Ibaraki 319-1195, Japan
| | - J K Woo
- Department of Physics, Jeju National University, Jeju 63243, Republic of Korea
| | - T Yamanaka
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - H Y Yoshida
- Department of Physics, Yamagata University, Yamagata 990-8560, Japan
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22
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Kokado R, Hagiya H, Morii D, Okuno H, Yamamoto N, Hamaguchi S, Yoshida H, Miwa Y, Tomono K. Broad-spectrum antibiotic prescriptions are discontinued unevenly throughout the week. J Hosp Infect 2018; 101:471-474. [PMID: 30423412 DOI: 10.1016/j.jhin.2018.11.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [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: 09/02/2018] [Accepted: 11/05/2018] [Indexed: 12/18/2022]
Abstract
In order to investigate prescribing patterns of in-hospital broad-spectrum antibiotics (antimeticillin-resistant Staphylococcus aureus drugs, carbapenems and piperacillin/tazobactam), data on the distribution of antibiotic initiation and discontinuation throughout the week were analysed at Osaka University Hospital, Japan. No significant differences in the number of initiations were found between weekdays. However, broad-spectrum antibiotics were disproportionately discontinued on Tuesdays or on the second day after a holiday. This study suggests that broad-spectrum antibiotics tend to be continued over weekends or holidays and discontinued thereafter; this is likely to be due to behavioural factors beyond medical indications, and needs to be addressed in future antimicrobial stewardship initiatives.
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Affiliation(s)
- R Kokado
- Division of Infection Control and Prevention, Osaka University Hospital, Osaka, Japan; Department of Pharmacy, Osaka University Hospital, Osaka, Japan
| | - H Hagiya
- Division of Infection Control and Prevention, Osaka University Hospital, Osaka, Japan.
| | - D Morii
- Division of Infection Control and Prevention, Osaka University Hospital, Osaka, Japan
| | - H Okuno
- Division of Infection Control and Prevention, Osaka University Hospital, Osaka, Japan
| | - N Yamamoto
- Division of Infection Control and Prevention, Osaka University Hospital, Osaka, Japan
| | - S Hamaguchi
- Division of Infection Control and Prevention, Osaka University Hospital, Osaka, Japan
| | - H Yoshida
- Division of Infection Control and Prevention, Osaka University Hospital, Osaka, Japan
| | - Y Miwa
- Department of Pharmacy, Osaka University Hospital, Osaka, Japan
| | - K Tomono
- Division of Infection Control and Prevention, Osaka University Hospital, Osaka, Japan
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23
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Alvarez CJ, Dau MT, Marty A, Vergnaud C, Le Poche H, Pochet P, Jamet M, Okuno H. Impact of a van der Waals interface on intrinsic and extrinsic defects in an MoSe 2 monolayer. Nanotechnology 2018; 29:425706. [PMID: 30052205 DOI: 10.1088/1361-6528/aad66f] [Citation(s) in RCA: 3] [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] [Indexed: 06/08/2023]
Abstract
In this work, we study growth and migration of atomic defects in MoSe2 on graphene using multiple advanced transmission electron microscopy techniques to explore defect behavior in vdW heterostructures. A MoSe2/graphene vdW heterostructure is prepared by a direct growth of both monolayers, thereby attaining an ideal vdW interface between the monolayers. We investigate the intrinsic defects (inversion domains and grain boundaries) in synthesized MoSe2, their evolution amid growth processing steps, and their influence on the formation and movement of extrinsic defects. Electron diffraction identifies a preferential interlayer orientation of 2° between MoSe2 and graphene, which is caused by the presence of intrinsic IBD defects. Extrinsic defects (point and line defects) are generated by in situ electron irradiation in the MoSe2 layer. Our results shed light on how to independently modify the MoSe2 atomic structure in vdW heterostructures for potential utilization in device processing.
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24
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Tsipas P, Tsoutsou D, Fragkos S, Sant R, Alvarez C, Okuno H, Renaud G, Alcotte R, Baron T, Dimoulas A. Massless Dirac Fermions in ZrTe 2 Semimetal Grown on InAs(111) by van der Waals Epitaxy. ACS Nano 2018; 12:1696-1703. [PMID: 29314824 DOI: 10.1021/acsnano.7b08350] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Single and few layers of the two-dimensional (2D) semimetal ZrTe2 are grown by molecular beam epitaxy on InAs(111)/Si(111) substrates. Excellent rotational commensurability, van der Waals gap at the interface and moiré pattern are observed indicating good registry between the ZrTe2 epilayer and the substrate through weak van der Waals forces. The electronic band structure imaged by angle resolved photoelectron spectroscopy shows that valence and conduction bands cross at the Fermi level exhibiting abrupt linear dispersions. The latter indicates massless Dirac Fermions which are maintained down to the 2D limit suggesting that single-layer ZrTe2 could be considered as the electronic analogue of graphene.
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Affiliation(s)
- Polychronis Tsipas
- National Center for Scientific Research "Demokritos" , 15310 Athens, Greece
| | - Dimitra Tsoutsou
- National Center for Scientific Research "Demokritos" , 15310 Athens, Greece
| | - Sotirios Fragkos
- National Center for Scientific Research "Demokritos" , 15310 Athens, Greece
| | - Roberto Sant
- University Grenoble Alpes , 38400 Grenoble, France
- Néel Institute, CNRS , 38042 Grenoble, France
| | - Carlos Alvarez
- University Grenoble Alpes , 38400 Grenoble, France
- CEA/INAC-MEM , F-38054 Grenoble Cedex 9, France
| | - Hanako Okuno
- University Grenoble Alpes , 38400 Grenoble, France
- CEA/INAC-MEM , F-38054 Grenoble Cedex 9, France
| | - Gilles Renaud
- University Grenoble Alpes , 38400 Grenoble, France
- CEA/INAC-MEM , F-38054 Grenoble Cedex 9, France
| | - Reynald Alcotte
- Universite Grenoble Alpes, CNRS, CEA/Leti Minatec, LTM , F-38054 Grenoble Cedex 9, France
| | - Thierry Baron
- Universite Grenoble Alpes, CNRS, CEA/Leti Minatec, LTM , F-38054 Grenoble Cedex 9, France
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25
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Hanana M, Arcostanzo H, Das PK, Bouget M, Le Gac S, Okuno H, Cornut R, Jousselme B, Dorcet V, Boitrel B, Campidelli S. Synergic effect on oxygen reduction reaction of strapped iron porphyrins polymerized around carbon nanotubes. NEW J CHEM 2018. [DOI: 10.1039/c8nj04516j] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Carbon nanotube-strapped iron porphyrin hybrids have been synthesized and their electrocatalytic activities for the oxygen reduction reaction have been investigated.
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Affiliation(s)
| | | | - Pradip K. Das
- Univ Rennes
- CNRS
- ISCR (Institut des Sciences Chimiques de Rennes)
- Rennes F-35000
- France
| | - Morgane Bouget
- Univ Rennes
- CNRS
- ISCR (Institut des Sciences Chimiques de Rennes)
- Rennes F-35000
- France
| | - Stéphane Le Gac
- Univ Rennes
- CNRS
- ISCR (Institut des Sciences Chimiques de Rennes)
- Rennes F-35000
- France
| | - Hanako Okuno
- University Grenoble Alpes
- CEA INAC-MEM
- F-38000 Grenoble
- France
| | | | | | - Vincent Dorcet
- Univ Rennes
- CNRS
- ISCR (Institut des Sciences Chimiques de Rennes)
- Rennes F-35000
- France
| | - Bernard Boitrel
- Univ Rennes
- CNRS
- ISCR (Institut des Sciences Chimiques de Rennes)
- Rennes F-35000
- France
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26
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Cadot S, Renault O, Frégnaux M, Rouchon D, Nolot E, Szeto K, Thieuleux C, Veyre L, Okuno H, Martin F, Quadrelli EA. A novel 2-step ALD route to ultra-thin MoS 2 films on SiO 2 through a surface organometallic intermediate. Nanoscale 2017; 9:538-546. [PMID: 27762415 DOI: 10.1039/c6nr06021h] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The lack of scalable-methods for the growth of 2D MoS2 crystals, an identified emerging material with applications ranging from electronics to energy storage, is a current bottleneck against its large-scale deployment. We report here a two-step ALD route with new organometallic precursors, Mo(NMe2)4 and 1,2-ethanedithiol (HS(CH2)2SH) which consists in the layer-by-layer deposition of an amorphous surface Mo(iv) thiolate at 50 °C, followed by a subsequent annealing at higher temperature leading to ultra-thin MoS2 nanocrystals (∼20 nm-large) in the 1-2 monolayer range. In contrast to the usual high-temperature growth of 2D dichalcogenides, where nucleation is the key parameter to control both thickness and uniformity, our novel two-step ALD approach enables chemical control over these two parameters, the growth of 2D MoS2 crystals upon annealing being ensured by spatial confinement and facilitated by the formation of a buffer oxysulfide interlayer.
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Affiliation(s)
- Stéphane Cadot
- Univ. Grenoble Alpes, FR-38000 Grenoble, CEA, LETI, Minatec Campus, FR-38054 Grenoble Cedex 9, France. and Université de Lyon, C2P2 - UMR 5265 (CNRS - Université de Lyon 1 - CPE Lyon), Équipe Chimie Organométallique de Surface CPE Lyon, 43 Boulevard du 11 Novembre 1918, FR-69616 Villeurbanne Cedex, France.
| | - Olivier Renault
- Univ. Grenoble Alpes, FR-38000 Grenoble, CEA, LETI, Minatec Campus, FR-38054 Grenoble Cedex 9, France.
| | - Mathieu Frégnaux
- Univ. Grenoble Alpes, FR-38000 Grenoble, CEA, LETI, Minatec Campus, FR-38054 Grenoble Cedex 9, France.
| | - Denis Rouchon
- Univ. Grenoble Alpes, FR-38000 Grenoble, CEA, LETI, Minatec Campus, FR-38054 Grenoble Cedex 9, France.
| | - Emmanuel Nolot
- Univ. Grenoble Alpes, FR-38000 Grenoble, CEA, LETI, Minatec Campus, FR-38054 Grenoble Cedex 9, France.
| | - Kai Szeto
- Université de Lyon, C2P2 - UMR 5265 (CNRS - Université de Lyon 1 - CPE Lyon), Équipe Chimie Organométallique de Surface CPE Lyon, 43 Boulevard du 11 Novembre 1918, FR-69616 Villeurbanne Cedex, France.
| | - Chloé Thieuleux
- Université de Lyon, C2P2 - UMR 5265 (CNRS - Université de Lyon 1 - CPE Lyon), Équipe Chimie Organométallique de Surface CPE Lyon, 43 Boulevard du 11 Novembre 1918, FR-69616 Villeurbanne Cedex, France.
| | - Laurent Veyre
- Université de Lyon, C2P2 - UMR 5265 (CNRS - Université de Lyon 1 - CPE Lyon), Équipe Chimie Organométallique de Surface CPE Lyon, 43 Boulevard du 11 Novembre 1918, FR-69616 Villeurbanne Cedex, France.
| | - Hanako Okuno
- Univ. Grenoble Alpes, FR-38000 Grenoble, CEA, INAC, SP2 M, Minatec Campus, FR-38054 Grenoble Cedex 9, France
| | - François Martin
- Univ. Grenoble Alpes, FR-38000 Grenoble, CEA, LETI, Minatec Campus, FR-38054 Grenoble Cedex 9, France.
| | - Elsje Alessandra Quadrelli
- Université de Lyon, C2P2 - UMR 5265 (CNRS - Université de Lyon 1 - CPE Lyon), Équipe Chimie Organométallique de Surface CPE Lyon, 43 Boulevard du 11 Novembre 1918, FR-69616 Villeurbanne Cedex, France.
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27
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Arias-Zapata J, Ferrah D, Garnier J, Böhme S, Mouray O, Okuno H, Cunge G, Zelsmann M. Graphene structuration by self-assembly of high-χ block copolymers. ACTA ACUST UNITED AC 2017. [DOI: 10.1016/j.matpr.2017.07.010] [Citation(s) in RCA: 2] [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: 11/30/2022]
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Oyarzún S, Nandy AK, Rortais F, Rojas-Sánchez JC, Dau MT, Noël P, Laczkowski P, Pouget S, Okuno H, Vila L, Vergnaud C, Beigné C, Marty A, Attané JP, Gambarelli S, George JM, Jaffrès H, Blügel S, Jamet M. Evidence for spin-to-charge conversion by Rashba coupling in metallic states at the Fe/Ge(111) interface. Nat Commun 2016; 7:13857. [PMID: 27976747 PMCID: PMC5171917 DOI: 10.1038/ncomms13857] [Citation(s) in RCA: 32] [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: 07/29/2016] [Accepted: 11/04/2016] [Indexed: 12/13/2022] Open
Abstract
The spin-orbit coupling relating the electron spin and momentum allows for spin generation, detection and manipulation. It thus fulfils the three basic functions of the spin field-effect transistor. However, the spin Hall effect in bulk germanium is too weak to produce spin currents, whereas large Rashba effect at Ge(111) surfaces covered with heavy metals could generate spin-polarized currents. The Rashba spin splitting can actually be as large as hundreds of meV. Here we show a giant spin-to-charge conversion in metallic states at the Fe/Ge(111) interface due to the Rashba coupling. We generate very large charge currents by direct spin pumping into the interface states from 20 K to room temperature. The presence of these metallic states at the Fe/Ge(111) interface is demonstrated by first-principles electronic structure calculations. By this, we demonstrate how to take advantage of the spin-orbit coupling for the development of the spin field-effect transistor.
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Affiliation(s)
- S Oyarzún
- Institut des Nanosciences et l'Energie Atomique et Cryogénie, INAC, Commissariat á aux Energies Alternatives-Univ. Grenoble Alpes, 17 rue des Martyrs, F-38000 Grenoble, France
- CEA, INAC, F-38000 Grenoble, France
- Departamento de Fisica, CEDENNA, Universidad de Santiago de Chile (USACH), 9170124 Santiago, Chile
| | - A K Nandy
- Peter Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany
| | - F Rortais
- Institut des Nanosciences et l'Energie Atomique et Cryogénie, INAC, Commissariat á aux Energies Alternatives-Univ. Grenoble Alpes, 17 rue des Martyrs, F-38000 Grenoble, France
- CEA, INAC, F-38000 Grenoble, France
| | - J-C Rojas-Sánchez
- Unité Mixte de Physique, CNRS, Thales, Univ. Paris-Sud, Université Paris-Saclay, 91767, Palaiseau, France
| | - M-T Dau
- Institut des Nanosciences et l'Energie Atomique et Cryogénie, INAC, Commissariat á aux Energies Alternatives-Univ. Grenoble Alpes, 17 rue des Martyrs, F-38000 Grenoble, France
- CEA, INAC, F-38000 Grenoble, France
| | - P Noël
- Institut des Nanosciences et l'Energie Atomique et Cryogénie, INAC, Commissariat á aux Energies Alternatives-Univ. Grenoble Alpes, 17 rue des Martyrs, F-38000 Grenoble, France
- CEA, INAC, F-38000 Grenoble, France
| | - P Laczkowski
- Unité Mixte de Physique, CNRS, Thales, Univ. Paris-Sud, Université Paris-Saclay, 91767, Palaiseau, France
| | - S Pouget
- Institut des Nanosciences et l'Energie Atomique et Cryogénie, INAC, Commissariat á aux Energies Alternatives-Univ. Grenoble Alpes, 17 rue des Martyrs, F-38000 Grenoble, France
- CEA, INAC, F-38000 Grenoble, France
| | - H Okuno
- Institut des Nanosciences et l'Energie Atomique et Cryogénie, INAC, Commissariat á aux Energies Alternatives-Univ. Grenoble Alpes, 17 rue des Martyrs, F-38000 Grenoble, France
- CEA, INAC, F-38000 Grenoble, France
| | - L Vila
- Institut des Nanosciences et l'Energie Atomique et Cryogénie, INAC, Commissariat á aux Energies Alternatives-Univ. Grenoble Alpes, 17 rue des Martyrs, F-38000 Grenoble, France
- CEA, INAC, F-38000 Grenoble, France
| | - C Vergnaud
- Institut des Nanosciences et l'Energie Atomique et Cryogénie, INAC, Commissariat á aux Energies Alternatives-Univ. Grenoble Alpes, 17 rue des Martyrs, F-38000 Grenoble, France
- CEA, INAC, F-38000 Grenoble, France
| | - C Beigné
- Institut des Nanosciences et l'Energie Atomique et Cryogénie, INAC, Commissariat á aux Energies Alternatives-Univ. Grenoble Alpes, 17 rue des Martyrs, F-38000 Grenoble, France
- CEA, INAC, F-38000 Grenoble, France
| | - A Marty
- Institut des Nanosciences et l'Energie Atomique et Cryogénie, INAC, Commissariat á aux Energies Alternatives-Univ. Grenoble Alpes, 17 rue des Martyrs, F-38000 Grenoble, France
- CEA, INAC, F-38000 Grenoble, France
| | - J-P Attané
- Institut des Nanosciences et l'Energie Atomique et Cryogénie, INAC, Commissariat á aux Energies Alternatives-Univ. Grenoble Alpes, 17 rue des Martyrs, F-38000 Grenoble, France
- CEA, INAC, F-38000 Grenoble, France
| | - S Gambarelli
- Institut des Nanosciences et l'Energie Atomique et Cryogénie, INAC, Commissariat á aux Energies Alternatives-Univ. Grenoble Alpes, 17 rue des Martyrs, F-38000 Grenoble, France
- CEA, INAC, F-38000 Grenoble, France
| | - J-M George
- Unité Mixte de Physique, CNRS, Thales, Univ. Paris-Sud, Université Paris-Saclay, 91767, Palaiseau, France
| | - H Jaffrès
- Unité Mixte de Physique, CNRS, Thales, Univ. Paris-Sud, Université Paris-Saclay, 91767, Palaiseau, France
| | - S Blügel
- Peter Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany
| | - M Jamet
- Institut des Nanosciences et l'Energie Atomique et Cryogénie, INAC, Commissariat á aux Energies Alternatives-Univ. Grenoble Alpes, 17 rue des Martyrs, F-38000 Grenoble, France
- CEA, INAC, F-38000 Grenoble, France
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Bengtson S, Kling K, Madsen AM, Noergaard AW, Jacobsen NR, Clausen PA, Alonso B, Pesquera A, Zurutuza A, Ramos R, Okuno H, Dijon J, Wallin H, Vogel U. No cytotoxicity or genotoxicity of graphene and graphene oxide in murine lung epithelial FE1 cells in vitro. Environ Mol Mutagen 2016; 57:469-82. [PMID: 27189646 PMCID: PMC5084775 DOI: 10.1002/em.22017] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 04/08/2016] [Indexed: 05/21/2023]
Abstract
Graphene and graphene oxide receive much attention these years, because they add attractive properties to a wide range of applications and products. Several studies have shown toxicological effects of other carbon-based nanomaterials such as carbon black nanoparticles and carbon nanotubes in vitro and in vivo. Here, we report in-depth physicochemical characterization of three commercial graphene materials, one graphene oxide (GO) and two reduced graphene oxides (rGO) and assess cytotoxicity and genotoxicity in the murine lung epithelial cell line FE1. The studied GO and rGO mainly consisted of 2-3 graphene layers with lateral sizes of 1-2 µm. GO had almost equimolar content of C, O, and H while the two rGO materials had lower contents of oxygen with C/O and C/H ratios of 8 and 12.8, respectively. All materials had low levels of endotoxin and low levels of inorganic impurities, which were mainly sulphur, manganese, and silicon. GO generated more ROS than the two rGO materials, but none of the graphene materials influenced cytotoxicity in terms of cell viability and cell proliferation after 24 hr. Furthermore, no genotoxicity was observed using the alkaline comet assay following 3 or 24 hr of exposure. We demonstrate that chemically pure, few-layered GO and rGO with comparable lateral size (> 1 µm) do not induce significant cytotoxicity or genotoxicity in FE1 cells at relatively high doses (5-200 µg/ml). Environ. Mol. Mutagen. 57:469-482, 2016. © 2016 The Authors. Environmental and Molecular Mutagenesis Published by Wiley Periodicals, Inc.
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Affiliation(s)
- Stefan Bengtson
- National Research Centre for the Working EnvironmentLersø Parkallé 105, DK‐2100Copenhagen ØDenmark
- Department of Science and EnvironmentRoskilde UniversityDK‐4000RoskildeDenmark
| | - Kirsten Kling
- National Research Centre for the Working EnvironmentLersø Parkallé 105, DK‐2100Copenhagen ØDenmark
| | - Anne Mette Madsen
- National Research Centre for the Working EnvironmentLersø Parkallé 105, DK‐2100Copenhagen ØDenmark
| | - Asger W. Noergaard
- National Research Centre for the Working EnvironmentLersø Parkallé 105, DK‐2100Copenhagen ØDenmark
| | - Nicklas Raun Jacobsen
- National Research Centre for the Working EnvironmentLersø Parkallé 105, DK‐2100Copenhagen ØDenmark
| | - Per Axel Clausen
- National Research Centre for the Working EnvironmentLersø Parkallé 105, DK‐2100Copenhagen ØDenmark
| | - Beatriz Alonso
- R&D DepartmentGraphenea S.ATolosa Hiribidea 76, E‐20018 DonostiaSan SebastianSpain
| | - Amaia Pesquera
- R&D DepartmentGraphenea S.ATolosa Hiribidea 76, E‐20018 DonostiaSan SebastianSpain
| | - Amaia Zurutuza
- R&D DepartmentGraphenea S.ATolosa Hiribidea 76, E‐20018 DonostiaSan SebastianSpain
| | - Raphael Ramos
- CEA GRENOBLE, University Grenoble AlpesF‐38000 GrenobleFrance
- Nanomaterials Technologies DepartmentCEA/LITEN/DTNM17 avenue des martyrs 38054 Grenoble cedex
| | - Hanako Okuno
- CEA GRENOBLE, University Grenoble AlpesF‐38000 GrenobleFrance
- Nanoscience and Cryogeny Institute CEA/DRF/INAC/MEM17 avenue des martyrs 38054 Grenoble cedex
| | - Jean Dijon
- CEA GRENOBLE, University Grenoble AlpesF‐38000 GrenobleFrance
- Nanomaterials Technologies DepartmentCEA/LITEN/DTNM17 avenue des martyrs 38054 Grenoble cedex
| | - Håkan Wallin
- National Research Centre for the Working EnvironmentLersø Parkallé 105, DK‐2100Copenhagen ØDenmark
- Department of Public HealthUniversity of CopenhagenDK‐1014Copenhagen KDenmark
| | - Ulla Vogel
- National Research Centre for the Working EnvironmentLersø Parkallé 105, DK‐2100Copenhagen ØDenmark
- Department of Micro‐ and NanotechnologyTechnical University of DenmarkDK‐2800 KgsLyngbyDenmark
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Takacs H, Viala B, Hermán V, Tortai JH, Duclairoir F, Alarcon Ramos J, Jouneau PH, Okuno H, Tallec G. Non-conductive ferromagnets based on core double-shell nanoparticles for radio-electric applications. Springerplus 2016; 5:496. [PMID: 27186460 PMCID: PMC4840130 DOI: 10.1186/s40064-016-2099-3] [Citation(s) in RCA: 2] [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] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Accepted: 04/05/2016] [Indexed: 11/16/2022]
Abstract
Two fabrication schemes of magnetic metal-polymer nanocomposites films are described. The nanocomposites are made of graphene-coated cobalt nanoparticles embedded in a polystyrene matrix. Scheme 1 uses non-covalent chemistry while scheme 2 involves covalent bonding with radicals. Preservation of the net-moment of cobalt and electrical insulation are achieved by means of a core double-shell structure of cobalt–graphene–polystyrene. The graphene shell has two functions: it is a protective layer against metal core oxidation and it serves as the functionalization surface for polymer grafting as well. The polystyrene shell is used as an insulating layer between nanoparticles and improves nanoparticles dispersion inside the polystyrene matrix. The theoretical maximum volume filling ratio estimated at ~30 % is almost reached. The nanocomposites are shown to undergo percolation behavior but retain low conductivity (<1 S/m) at the highest filling ratio reached ~25 % leading to extremely low losses (10−3) at high frequency. Such low conductivity values are combined with large magnetization, as high as 0.9 T. Ability for radiofrequency applications is discussed in regards to the obtained magnetization.
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Affiliation(s)
- Hélène Takacs
- LETI, CEA, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France ; LTM, CNRS-UJF, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Bernard Viala
- LETI, CEA, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Vanessa Hermán
- LETI, CEA, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Jean-Hervé Tortai
- LTM, CNRS-UJF, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Florence Duclairoir
- INAC, CEA, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France ; INAC, Univ. Grenoble Alpes, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | | | | | - Hanako Okuno
- INAC, CEA, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Gwenolé Tallec
- Visualization Sciences Group, FEI, 3 Impasse Rudolf Diesel, 33700 Mérignac, France
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31
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Medina JDLT, Hamoir G, Velázquez-Galván Y, Pouget S, Okuno H, Vila L, Encinas A, Piraux L. Large magnetic anisotropy enhancement in size controlled Ni nanowires electrodeposited into nanoporous alumina templates. Nanotechnology 2016; 27:145702. [PMID: 26906237 DOI: 10.1088/0957-4484/27/14/145702] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A large enhancement of the magnetic anisotropy of Ni nanowires (NWs) embedded in anodic aluminium oxide porous membranes is obtained as a result of an induced magnetoelastic (ME) anisotropy contribution. This unusual large anisotropy enhancement depends on the diameter of the NWs and exceeds the magnetostatic (MS) contribution. As a consequence, it leads to effective magnetic anisotropy energies as large as 1.4 × 10(6) erg cm(-3), which are of the same order of magnitude and comparable to the MS energies of harder magnetic materials like Co NWs. Specifically, from ferromagnetic resonance experiments, the magnetic anisotropy of the NWs has been observed to increase as its diameter is decreased, leading to values that are about four times larger than the corresponding value when only the MS anisotropy is present. Our results are consistent with the recently proposed growth mechanism of Ni NWs that proceeds via a poly-crystalline stage at the bottom followed by a single-crystalline stage with texture [110] parallel to the axis of the NWs. A strong correlation between reducing the diameter of the NWs with the decrease of the length of the poly-crystalline segment and the enhancement of the effective magnetic anisotropy has been shown. Magnetization curves obtained from alternating gradient magnetometry experiments show that the average ME anisotropy results from the competition between the magnetic anisotropies of both crystalline segments of the NWs. Understanding the influence of size and confinement effects on the magnetic properties of nanocomposites is of prime interest for the development of novel and agile devices.
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Affiliation(s)
- J De La Torre Medina
- Instituto de Investigaciones en Materiales-Unidad Morelia, Universidad Nacional Autónoma de México. Antigua Carretera a Pátzcuaro No. 8701 Col. Ex Hacienda de San José de la Huerta, C. P. 58190, Morelia, Mexico
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32
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Ferrah D, Renault O, Petit-Etienne C, Okuno H, Berne C, Bouchiat V, Cunge G. XPS investigations of graphene surface cleaning using H2- and Cl2-based inductively coupled plasma. SURF INTERFACE ANAL 2016. [DOI: 10.1002/sia.6010] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- D. Ferrah
- Univ. Grenoble Alpes; F-38000 Grenoble France
- CEA, LETI, Minatec Campus; F-38054 Grenoble France
- LTM-CNRS, Minatec Campus; F-38054 Grenoble France
| | - O. Renault
- Univ. Grenoble Alpes; F-38000 Grenoble France
- CEA, LETI, Minatec Campus; F-38054 Grenoble France
| | - C. Petit-Etienne
- Univ. Grenoble Alpes; F-38000 Grenoble France
- LTM-CNRS, Minatec Campus; F-38054 Grenoble France
| | - H. Okuno
- Univ. Grenoble Alpes; F-38000 Grenoble France
- INAC-CNRS, Minatec Campus; F-38054 Grenoble France
| | - C. Berne
- Univ. Grenoble Alpes; F-38000 Grenoble France
- Institut Néel, CNRS-UJF; BP 166 38042 Grenoble cedex 9 France
| | - V. Bouchiat
- Univ. Grenoble Alpes; F-38000 Grenoble France
- Institut Néel, CNRS-UJF; BP 166 38042 Grenoble cedex 9 France
| | - G. Cunge
- Univ. Grenoble Alpes; F-38000 Grenoble France
- LTM-CNRS, Minatec Campus; F-38054 Grenoble France
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Lee D, Kaushik M, Coustel R, Chenavier Y, Chanal M, Bardet M, Dubois L, Okuno H, Rochat N, Duclairoir F, Mouesca J, De Paëpe G. Solid‐State NMR and DFT Combined for the Surface Study of Functionalized Silicon Nanoparticles. Chemistry 2015; 21:16047-58. [DOI: 10.1002/chem.201502687] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Indexed: 11/07/2022]
Affiliation(s)
- Daniel Lee
- Univsité Grenoble Alpes, 38000 Grenoble (France)
- CEA, INAC, SCIB, 38000 Grenoble (France)
| | - Monu Kaushik
- Univsité Grenoble Alpes, 38000 Grenoble (France)
- CEA, INAC, SCIB, 38000 Grenoble (France)
- Present address: Institutes of Biophysical Chemistry, Physical and Theoretical Chemistry and Center for Biomolecular Magnetic Resonance BMRZ, Goethe University Frankfurt, 60438 Frankfurt/M. (Germany)
| | - Romain Coustel
- Univsité Grenoble Alpes, 38000 Grenoble (France)
- CEA, INAC, SCIB, 38000 Grenoble (France)
- Present address: Université de Lorraine, LCPME, UMR 7564, Villers‐les‐Nancy 54600 (France)
| | - Yves Chenavier
- Univsité Grenoble Alpes, 38000 Grenoble (France)
- CEA, INAC, SCIB, 38000 Grenoble (France)
| | - Myriam Chanal
- Univsité Grenoble Alpes, 38000 Grenoble (France)
- CEA, INAC, SCIB, 38000 Grenoble (France)
| | - Michel Bardet
- Univsité Grenoble Alpes, 38000 Grenoble (France)
- CEA, INAC, SCIB, 38000 Grenoble (France)
| | - Lionel Dubois
- Univsité Grenoble Alpes, 38000 Grenoble (France)
- CEA, INAC, SCIB, 38000 Grenoble (France)
| | - Hanako Okuno
- Univsité Grenoble Alpes, 38000 Grenoble (France)
- CEA, INAC, SP2M, 38000 Grenoble (France)
| | - Névine Rochat
- Univsité Grenoble Alpes, 38000 Grenoble (France)
- CEA‐LETI, MINATEC Campus, 38054 Grenoble (France)
| | - Florence Duclairoir
- Univsité Grenoble Alpes, 38000 Grenoble (France)
- CEA, INAC, SCIB, 38000 Grenoble (France)
| | - Jean‐Marie Mouesca
- Univsité Grenoble Alpes, 38000 Grenoble (France)
- CEA, INAC, SCIB, 38000 Grenoble (France)
| | - Gaël De Paëpe
- Univsité Grenoble Alpes, 38000 Grenoble (France)
- CEA, INAC, SCIB, 38000 Grenoble (France)
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Okuno H, Greene J, Hasebe H, Imao H, Storalrz A, Yoshida A. Foreword of the 27th world conference of the international nuclear target. J Radioanal Nucl Chem 2015. [DOI: 10.1007/s10967-015-4358-0] [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: 11/28/2022]
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35
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Koga T, Okada A, Kawakami A, Fukuda T, Hidaka T, Ishii T, Ueki Y, Kodera T, Nakashima M, Takahashi Y, Honda S, Watanabe R, Okuno H, Tamai M, Aoyagi K, Eguchi K. SAT0088 Prognostic Factors Toward Rapid Radiographic Progression in Patients with Rheumatoid Arthritis in Clinical Practice: A Japanese Multicenter, Prospective Longitudinal Cohort Study for Achieving Treat to Target Strategy. Ann Rheum Dis 2015. [DOI: 10.1136/annrheumdis-2015-eular.2201] [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: 11/04/2022]
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Tinoco M, Fernandez-Garcia S, Lopez-Haro M, Hungria AB, Chen X, Blanco G, Perez-Omil JA, Collins SE, Okuno H, Calvino JJ. Critical Influence of Nanofaceting on the Preparation and Performance of Supported Gold Catalysts. ACS Catal 2015. [DOI: 10.1021/acscatal.5b00086] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Miguel Tinoco
- Departamento
de Ciencia de los Materiales e Ingeniería Metalúrgica
y Química Inorgánica, Facultad de Ciencias, Universidad de Cadiz, Campus Río San Pedro, E-11510, Puerto Real, Cádiz, Spain
| | - Susana Fernandez-Garcia
- Departamento
de Ciencia de los Materiales e Ingeniería Metalúrgica
y Química Inorgánica, Facultad de Ciencias, Universidad de Cadiz, Campus Río San Pedro, E-11510, Puerto Real, Cádiz, Spain
| | - Miguel Lopez-Haro
- Departamento
de Ciencia de los Materiales e Ingeniería Metalúrgica
y Química Inorgánica, Facultad de Ciencias, Universidad de Cadiz, Campus Río San Pedro, E-11510, Puerto Real, Cádiz, Spain
- University Grenoble Alpes, INAC-SP2M, and CEA, INAC-SP2M, LEMMA, F-38000 Grenoble, France
| | - Ana B. Hungria
- Departamento
de Ciencia de los Materiales e Ingeniería Metalúrgica
y Química Inorgánica, Facultad de Ciencias, Universidad de Cadiz, Campus Río San Pedro, E-11510, Puerto Real, Cádiz, Spain
| | - Xiaowei Chen
- Departamento
de Ciencia de los Materiales e Ingeniería Metalúrgica
y Química Inorgánica, Facultad de Ciencias, Universidad de Cadiz, Campus Río San Pedro, E-11510, Puerto Real, Cádiz, Spain
| | - Ginesa Blanco
- Departamento
de Ciencia de los Materiales e Ingeniería Metalúrgica
y Química Inorgánica, Facultad de Ciencias, Universidad de Cadiz, Campus Río San Pedro, E-11510, Puerto Real, Cádiz, Spain
| | - Jose A. Perez-Omil
- Departamento
de Ciencia de los Materiales e Ingeniería Metalúrgica
y Química Inorgánica, Facultad de Ciencias, Universidad de Cadiz, Campus Río San Pedro, E-11510, Puerto Real, Cádiz, Spain
| | - Sebastian E. Collins
- Instituto de Desarrollo Tecnológico para la Industria Química (CONICET, UNL), Güemes,
3450, S3000GLN, Santa Fe, Argentina
| | - Hanako Okuno
- University Grenoble Alpes, INAC-SP2M, and CEA, INAC-SP2M, LEMMA, F-38000 Grenoble, France
| | - Jose J. Calvino
- Departamento
de Ciencia de los Materiales e Ingeniería Metalúrgica
y Química Inorgánica, Facultad de Ciencias, Universidad de Cadiz, Campus Río San Pedro, E-11510, Puerto Real, Cádiz, Spain
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Ohta T. Sugimoto T, Kiyasu Y, Hayashi K, Kojima C, Suzuki M, Ohashi A, Ueta Y, Matsushita T, Okuno H. PP165-MON: A New Challenge of the Evaluation of Malnutrition Using TSF (Triceps Skinfold Thickness) and AMC (Arm Muscle Circumference). Clin Nutr 2014. [DOI: 10.1016/s0261-5614(14)50499-2] [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: 11/26/2022]
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Okada A, Kawakami A, Fukuda T, Hidaka T, Ishii T, Ueki Y, Kodera T, Nakashima M, Takahashi Y, Honda S, Horai Y, Koga T, Tamai M, Aoyagi K, Watanabe R, Okuno H, Eguchi K. AB0219 Evaluation of the Japanese Patients with Rheumatoid Arthritis (RA) of RAPID Radiographic Progression (RRP) Treated with Synthetic Disease Modifying Anti-Rheumatic Drugs (DMARDS) in Daily Practice: A Large-Scale Prospective Longitudinal Cohort Study. Ann Rheum Dis 2014. [DOI: 10.1136/annrheumdis-2014-eular.4035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Somanathan T, Dijon J, Fournier A, Okuno H. Effective supergrowth of vertical aligned carbon nanotubes at low temperature and pressure. J Nanosci Nanotechnol 2014; 14:2520-2526. [PMID: 24745257 DOI: 10.1166/jnn.2014.8504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We present the generalised supergrowth of single and double walled carbon nanotubes like "water assisted supergrowth" at low temperature (630 degrees C) and pressure (1 Torr) by chemical vapour deposition using various thicknesses of iron supported alumina substrate as a catalyst. Reduced temperature and low pressure synthesis of single walled (SW) and double walled (DW) carbon nanotubes is of interest for their efficient growth into device architectures. Pure SW with 2.5 nm diameter are obtained with 0.37 nm Fe catalyst at 630 degrees C. We demonstrated the decrease of the density versus temperatures and also obtained high density materials (1.4 x 10(12) cm(-2)) at low temperature (580 degrees C). Scanning and transmission electron microscope studies provided information on the height, density of the carpets and the structure and diameter of SW and DW carbon nanotubes, respectively.
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Okada A, Kawakami A, Fukuda T, Hidaka T, Ishii T, Ueki Y, Kodera T, Nakashima M, Takahashi Y, Honda S, Horai Y, Koga T, Watanabe R, Okuno H, Eguchi K. THU0121 Characteristic of the Japanese Patients with Rheumatoid Arthritis (RA) of Rapid Radiographic Progression (RRP) Treated with Synthetic Disease Modifying Anti-Rheumatic Drugs (DMARDS) in Daily Practice: A Large-Scale Prospective Longitudinal Cohort Study. Ann Rheum Dis 2014. [DOI: 10.1136/annrheumdis-2013-eular.649] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Dijon J, Chiodarelli N, Fournier A, Okuno H, Ramos R. Horizontal carbon nanotube interconnects for advanced integrated circuits. ACTA ACUST UNITED AC 2013. [DOI: 10.1557/opl.2013.869] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
ABSTRACTHorizontal carbon nanotube (CNT) interconnects are fabricated using a novel integration scheme yielding record wall densities >1013 shell/cm2, i.e. close to the density required for implementation in advanced integrated circuits. The CNTs are grown vertically from individual via structure and subsequently flipped onto the horizontal wafer surface. Various electrode designs are then used to produce different geometries of metal-to-tube contact such as side contact or end contact. CNT lines - 50 to 100 nm wide and up to 20 µm long - are realized and electrically characterized. The sum of the contact resistances from both ends of the lines is close to 500 Ω for 100 nm diameter lines which leads to a specific contact resistance of 1.6 10-8 Ω.cm2 per tube. With the developed technology, post-annealing of the contact does not improve the resistance values. Both chromium and palladium are used as contact metal. While contact resistance is equivalent with the two metals, the resistance per unit length of the lines does change and is better with palladium. This dependence is explained using a tunnelling model which shows that statistics of individual tube-metal contact is required to properly model the electrical results. Direct experimental evidences showing that only a part of the CNTs in the bundle is electrically connected are also given. Our best line resistivity achieved is 1.6mΩ.cm which is among the best results published for horizontally aligned CNTs and the only one with a realistic geometry for future VLSI interconnects.
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Watanabe R, Okuno H, Ishii T, Harigae H, Hirabayashi Y. AB0330 Long-term administration of tocilizumab increases the structural remission rate year by year and continuously inhibits radiographic progression: 3 year results from michinoku tocilizumab study group. Ann Rheum Dis 2013. [DOI: 10.1136/annrheumdis-2013-eular.2652] [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: 11/04/2022]
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43
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Okuno H, Atagi K, Shimaoka H. Mortality related to respiratory failure among pediatric hematology patients requiring intensive care. Crit Care 2013. [PMCID: PMC3643103 DOI: 10.1186/cc12452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
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Ogata R, Suzuki S, Ahn JK, Akune Y, Baranov V, Chen KF, Comfort J, Doroshenko M, Fujioka Y, Hsiung YB, Inagaki T, Ishibashi S, Ishihara N, Ishii H, Iwai E, Iwata T, Kato I, Kobayashi S, Komatsu S, Komatsubara TK, Kurilin AS, Kuzmin E, Lednev A, Lee HS, Lee SY, Lim GY, Ma J, Matsumura T, Moisseenko A, Morii H, Morimoto T, Nakajima Y, Nakano T, Nanjo H, Nishi N, Nix J, Nomura T, Nomachi M, Okuno H, Omata K, Perdue GN, Perov S, Podolsky S, Porokhovoy S, Sakashita K, Sasaki T, Sasao N, Sato H, Sato T, Sekimoto M, Shimogawa T, Shinkawa T, Stepanenko Y, Sugaya Y, Sugiyama A, Sumida T, Tajima Y, Takita S, Tsamalaidze Z, Tsukamoto T, Tung YC, Wah YW, Watanabe H, Wu ML, Yamaga M, Yamanaka T, Yoshida HY, Yoshimura Y, Zheng Y. Study of theKL0→π0π0νν¯decay. Int J Clin Exp Med 2011. [DOI: 10.1103/physrevd.84.052009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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45
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Tung YC, Hsiung YB, Ahn JK, Akune Y, Baranov V, Chen KF, Comfort J, Doroshenko M, Fujioka Y, Inagaki T, Ishibashi S, Ishihara N, Ishii H, Iwai E, Iwata T, Kato I, Kobayashi S, Komatsu S, Komatsubara TK, Kurilin AS, Kuzmin E, Lednev A, Lee HS, Lee SY, Lim GY, Ma J, Matsumura T, Moisseenko A, Morii H, Morimoto T, Nakajima Y, Nakano T, Nanjo H, Nishi N, Nix J, Nomura T, Nomachi M, Ogata R, Okuno H, Omata K, Perdue GN, Perov S, Podolsky S, Porokhovoy S, Sakashita K, Sasaki T, Sasao N, Sato H, Sato T, Sekimoto M, Shimogawa T, Shinkawa T, Stepanenko Y, Sugaya Y, Sugiyama A, Sumida T, Suzuki S, Tajima Y, Takita S, Tsamalaidze Z, Tsukamoto T, Wah Y, Watanabe H, Wu ML, Yamaga M, Yamanaka T, Yoshida HY, Yoshimura Y, Zheng Y. Search for the decayKL0→3γ. Int J Clin Exp Med 2011. [DOI: 10.1103/physrevd.83.031101] [Citation(s) in RCA: 4] [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: 11/07/2022]
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46
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Ahn JK, Akune Y, Baranov V, Chen KF, Comfort J, Doroshenko M, Fujioka Y, Hsiung YB, Inagaki T, Ishibashi S, Ishihara N, Ishii H, Iwai E, Iwata T, Kato I, Kobayashi S, Komatsu S, Komatsubara TK, Kurilin AS, Kuzmin E, Lednev A, Lee HS, Lee SY, Lim GY, Ma J, Matsumura T, Moisseenko A, Morii H, Morimoto T, Nakajima Y, Nakano T, Nanjo H, Nishi N, Nix J, Nomura T, Nomachi M, Ogata R, Okuno H, Omata K, Perdue GN, Perov S, Podolsky S, Porokhovoy S, Sakashita K, Sasaki T, Sasao N, Sato H, Sato T, Sekimoto M, Shimogawa T, Shinkawa T, Stepanenko Y, Sugaya Y, Sugiyama A, Sumida T, Suzuki S, Tajima Y, Takita S, Tsamalaidze Z, Tsukamoto T, Tung YC, Wah YW, Watanabe H, Wu ML, Yamaga M, Yamanaka T, Yoshida HY, Yoshimura Y, Zheng Y. Experimental study of the decayKL0→π0νν¯. Int J Clin Exp Med 2010. [DOI: 10.1103/physrevd.81.072004] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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47
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Nakagawa T, Higurashi Y, Ohnishi J, Aihara T, Tamura M, Uchiyama A, Okuno H, Kusaka K, Kidera M, Ikezawa E, Fujimaki M, Sato Y, Watanabe Y, Komiyama M, Kase M, Goto A, Kamigaito O, Yano Y. First results from the new RIKEN superconducting electron cyclotron resonance ion source (invited). Rev Sci Instrum 2010; 81:02A320. [PMID: 20192341 DOI: 10.1063/1.3259232] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The next generation heavy ion accelerator facility, such as the RIKEN radio isotope (RI) beam factory, requires an intense beam of high charged heavy ions. In the past decade, performance of the electron cyclotron resonance (ECR) ion sources has been dramatically improved with increasing the magnetic field and rf frequency to enhance the density and confinement time of plasma. Furthermore, the effects of the key parameters (magnetic field configuration, gas pressure, etc.) on the ECR plasma have been revealed. Such basic studies give us how to optimize the ion source structure. Based on these studies and modern superconducting (SC) technology, we successfully constructed the new 28 GHz SC-ECRIS, which has a flexible magnetic field configuration to enlarge the ECR zone and to optimize the field gradient at ECR point. Using it, we investigated the effect of ECR zone size, magnetic field configuration, and biased disk on the beam intensity of the highly charged heavy ions with 18 GHz microwaves. In this article, we present the structure of the ion source and first experimental results with 18 GHz microwave in detail.
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Affiliation(s)
- T Nakagawa
- Nishina Center for Accelerator Based Science, RIKEN, Hirosawa 2-1, Wako, Saitama 351-0198, Japan
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Noé P, Okuno H, Jager JB, Delamadeleine E, Demichel O, Rouvière JL, Calvo V, Maurizio C, D'Acapito F. The evolution of the fraction of Er ions sensitized by Si nanostructures in silicon-rich silicon oxide thin films. Nanotechnology 2009; 20:355704. [PMID: 19671977 DOI: 10.1088/0957-4484/20/35/355704] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Photoluminescence (PL) and time-resolved PL experiments as a function of the elaboration process are performed on Er-doped silicon-rich silicon oxide (SRO:Er) thin films grown under NH(3) atmosphere. These PL measurements of the Er(3+) emission at 1.54 microm under non-resonant pumping with the Er f-f transitions are obtained for different Er(3+) concentrations, ranging from 0.05 to 1.4 at.%, and various post-growth annealing temperatures of the layers. High resolution transmission electron microscopy (HRTEM) and energy-filtered TEM (EFTEM) analysis show a high density of Si nanostructures composed of amorphous and crystalline nanoclusters varying from 2.7 x 10(18) to 10(18) cm(-3) as a function of the post-growth annealing temperature. Measurements of PL lifetime and effective Er excitation cross section for all the samples under non-resonant optical excitation with the Er(3+) atomic energy levels show that the number of Er(3+) ions sensitized by the silicon-rich matrix decreases as the annealing temperature is increased from 500 to 1050 degrees C. The origin of this effect is attributed to the reduction of the density of sensitizers for Er ions in the SRO matrix when the annealing temperature increases. Finally, extended x-ray absorption fine-structure spectroscopy (EXAFS) shows a strong correlation between the number of emitters and the mean local order around the erbium ions.
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Affiliation(s)
- P Noé
- INAC/SP2M, Commissariat à l'Energie Atomique-MINATEC, 17 rue des Martyrs, Grenoble Cedex, France
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49
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Tung YC, Hsiung YB, Wu ML, Chen KF, Ahn JK, Akune Y, Baranov V, Comfort J, Doroshenko M, Fujioka Y, Inagaki T, Ishibashi S, Ishihara N, Ishii H, Iwai E, Iwata T, Kato I, Kobayashi S, Komatsubara TK, Kurilin AS, Kuzmin E, Lednev A, Lee HS, Lee SY, Lim GY, Ma J, Matsumura T, Moisseenko A, Morii H, Morimoto T, Nakano T, Nanjo H, Nix J, Nomura T, Nomachi M, Ogata R, Okuno H, Omata K, Perdue GN, Podolsky S, Sakashita K, Sasaki T, Sasao N, Sato H, Sato T, Sekimoto M, Shinkawa T, Sugaya Y, Sugiyama A, Sumida T, Suzuki S, Tajima Y, Takita S, Tsamalaidze Z, Tsukamoto T, Wah Y, Watanabe H, Yamaga M, Yamanaka T, Yoshida HY, Yoshimura Y, Zheng Y. Search for a light pseudoscalar particle in the decay K_{L};{0}-->pi;{0}pi;{0}X. Phys Rev Lett 2009; 102:051802. [PMID: 19257503 DOI: 10.1103/physrevlett.102.051802] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2008] [Indexed: 05/27/2023]
Abstract
We performed a search for a light pseudoscalar particle X in the decay K_{L};{0}-->pi;{0}pi;{0}X, X-->gammagamma with the E391a detector at KEK. Such a particle with a mass of 214.3 MeV/c;{2} was suggested by the HyperCP experiment. We found no evidence for X and set an upper limit on the product branching ratio for K_{L};{0}-->pi;{0}pi;{0}X, X-->gammagamma of 2.4x10;{-7} at the 90% confidence level. Upper limits on the branching ratios in the mass region of X from 194.3 to 219.3 MeV/c;{2} are also presented.
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Affiliation(s)
- Y C Tung
- Department of Physics, National Taiwan University, Taipei, Taiwan
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50
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Okuno H, Takeguchi M, Mitsuishi K, Irokawa Y, Sakuma Y, Furuya K. Local characterizations of quaternary AlInGaN/GaN heterostructures using TEM and HAADF-STEM. SURF INTERFACE ANAL 2008. [DOI: 10.1002/sia.2960] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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