1
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Miura M, Eley S, Iida K, Hanzawa K, Matsumoto J, Hiramatsu H, Ogimoto Y, Suzuki T, Kobayashi T, Ozaki T, Kurokawa H, Sekiya N, Yoshida R, Kato T, Okada T, Okazaki H, Yamaki T, Hänisch J, Awaji S, Maeda A, Maiorov B, Hosono H. Quadrupling the depairing current density in the iron-based superconductor SmFeAsO 1-xH x. NATURE MATERIALS 2024:10.1038/s41563-024-01952-7. [PMID: 39026087 DOI: 10.1038/s41563-024-01952-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 06/20/2024] [Indexed: 07/20/2024]
Abstract
Iron-based 1111-type superconductors display high critical temperatures and relatively high critical current densities Jc. The typical approach to increasing Jc is to introduce defects to control dissipative vortex motion. However, when optimized, this approach is theoretically predicted to be limited to achieving a maximum Jc of only ∼30% of the depairing current density Jd, which depends on the coherence length and the penetration depth. Here we dramatically boost Jc in SmFeAsO1-xHx films using a thermodynamic approach aimed at increasing Jd and incorporating vortex pinning centres. Specifically, we reduce the penetration depth, coherence length and critical field anisotropy by increasing the carrier density through high electron doping using H substitution. Remarkably, the quadrupled Jd reaches 415 MA cm-2, a value comparable to cuprates. Finally, by introducing defects using proton irradiation, we obtain high Jc values in fields up to 25 T. We apply this method to other iron-based superconductors and achieve a similar enhancement of current densities.
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Affiliation(s)
- Masashi Miura
- Graduate School of Science and Technology, Seikei University, Tokyo, Japan.
- National High Magnetic Field Laboratory, Los Alamos National Laboratory, Los Alamos, NM, USA.
- Fusion Oriented REsearch for disruptive Science and Technology (FOREST), Japan Science and Technology Agency (JST), Tokyo, Japan.
| | - Serena Eley
- Department of Electrical & Computer Engineering, University of Washington, Seattle, WA, USA
- Department of Physics, Colorado School of Mines, Golden, CO, USA
| | - Kazumasa Iida
- College of Industrial Technology, Nihon University, Chiba, Japan
| | - Kota Hanzawa
- Laboratory for Materials and Structures, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Jumpei Matsumoto
- Laboratory for Materials and Structures, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Hidenori Hiramatsu
- Laboratory for Materials and Structures, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
- MDX Research Center for Element Strategy, International Research Frontiers Initiative, Tokyo Institute of Technology, Yokohama, Japan
| | - Yuki Ogimoto
- Graduate School of Science and Technology, Seikei University, Tokyo, Japan
| | - Takumi Suzuki
- Graduate School of Science and Technology, Seikei University, Tokyo, Japan
| | - Tomoki Kobayashi
- Department of Basic Science, The University of Tokyo, Tokyo, Japan
| | | | - Hodaka Kurokawa
- The Institute of Advanced Sciences, Yokohama National University, Yokohama, Japan
| | - Naoto Sekiya
- Department of Electrical and Electronic Engineering, University of Yamanashi, Kofu, Japan
| | - Ryuji Yoshida
- Nanostructures Research Laboratory, Japan Fine Ceramics Center, Nagoya, Japan
| | - Takeharu Kato
- Nanostructures Research Laboratory, Japan Fine Ceramics Center, Nagoya, Japan
| | - Tatsunori Okada
- Institute for Materials Research, Tohoku University, Sendai, Japan
| | - Hiroyuki Okazaki
- Takasaki Institute for Advanced Quantum Science, National Institutes for Quantum Science and Technology (QST), Takasaki, Japan
| | - Tetsuya Yamaki
- Takasaki Institute for Advanced Quantum Science, National Institutes for Quantum Science and Technology (QST), Takasaki, Japan
| | - Jens Hänisch
- Institute for Technical Physics, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
| | - Satoshi Awaji
- Institute for Materials Research, Tohoku University, Sendai, Japan
| | - Atsutaka Maeda
- Department of Basic Science, The University of Tokyo, Tokyo, Japan
| | - Boris Maiorov
- National High Magnetic Field Laboratory, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Hideo Hosono
- MDX Research Center for Element Strategy, International Research Frontiers Initiative, Tokyo Institute of Technology, Yokohama, Japan
- National Institute for Materials Science (NIMS), Tsukuba, Japan
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2
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Niu R, Li J, Zhen W, Xu F, Weng S, Yue Z, Meng X, Xia J, Hao N, Zhang C. Enhanced Superconductivity and Critical Current Density Due to the Interaction of InSe 2 Bonded Layer in (InSe 2) 0.12NbSe 2. J Am Chem Soc 2024; 146:1244-1249. [PMID: 38180816 PMCID: PMC10797615 DOI: 10.1021/jacs.3c09756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 01/02/2024] [Accepted: 01/03/2024] [Indexed: 01/07/2024]
Abstract
Superconductivity was discovered in (InSe2)xNbSe2. The materials are crystallized in a unique layered structure where bonded InSe2 layers are intercalated into the van der Waals gaps of 2H-phase NbSe2. The (InSe2)0.12NbSe2 superconductor exhibits a superconducting transition at 11.6 K and critical current density of 8.2 × 105 A/cm2. Both values are the highest among all transition metal dichalcogenide superconductors at ambient pressure. The present finding provides an ideal material platform for further investigation of superconducting-related phenomena in transition metal dichalcogenides.
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Affiliation(s)
- Rui Niu
- High
Magnetic Field Laboratory of Anhui Province, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
- Science
Island Branch of Graduate School, University
of Science and Technology of China, Hefei 230026, China
| | - Jiayang Li
- High
Magnetic Field Laboratory of Anhui Province, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
- Science
Island Branch of Graduate School, University
of Science and Technology of China, Hefei 230026, China
| | - Weili Zhen
- High
Magnetic Field Laboratory of Anhui Province, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
| | - Feng Xu
- High
Magnetic Field Laboratory of Anhui Province, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
| | - Shirui Weng
- High
Magnetic Field Laboratory of Anhui Province, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
| | - Zhilai Yue
- High
Magnetic Field Laboratory of Anhui Province, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
| | - Xiangmin Meng
- Key
Laboratory of Photochemical Conversion and Optoelectronic Materials,
Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Jing Xia
- Key
Laboratory of Photochemical Conversion and Optoelectronic Materials,
Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Ning Hao
- High
Magnetic Field Laboratory of Anhui Province, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
| | - Changjin Zhang
- High
Magnetic Field Laboratory of Anhui Province, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
- Collaborative
Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
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3
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Vlasenko VA, Degtyarenko AY, Shilov AI, Tsvetkov AY, Kulikova LF, Medvedev AS, Pervakov KS. Phase Formation of Iron-Based Superconductors during Mechanical Alloying. MATERIALS (BASEL, SWITZERLAND) 2022; 15:8438. [PMID: 36499936 PMCID: PMC9737871 DOI: 10.3390/ma15238438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 11/23/2022] [Accepted: 11/25/2022] [Indexed: 06/17/2023]
Abstract
We successfully synthesized bulk Ba0.6Na0.4Fe2As2 and Sr0.5Na0.5Fe2As2 compounds by high-energy mechanical alloying (MA) technique. The MA process results in homogeneous amorphous phases of BaFe2As2 and SrFe2As2. It was found that the optimum time for high-energy milling in all cases is about 1.5-2 h, and the maximum amount of amorphous phase could be obtained when energy of 50-100 MJ/kg was absorbed by the powder. After a short-term heat treatment, we obtained nearly optimum sodium-doped Ba1-xNaxFe2As2 and Sr1-xNaxFe2As2 superconducting bulk samples. Therefore, MA is a potential scalable method to produce bulk superconducting material for industrial needs.
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Affiliation(s)
- Vladimir A. Vlasenko
- V.L. Ginzburg Centre for High-Temperature Superconductivity and Quantum Materials, P.N. Lebedev Physical Institute of the Russian Academy of Sciences, 53, Leninsky Ave., 119991 Moscow, Russia
| | - Alena Yu. Degtyarenko
- V.L. Ginzburg Centre for High-Temperature Superconductivity and Quantum Materials, P.N. Lebedev Physical Institute of the Russian Academy of Sciences, 53, Leninsky Ave., 119991 Moscow, Russia
| | - Andrei I. Shilov
- V.L. Ginzburg Centre for High-Temperature Superconductivity and Quantum Materials, P.N. Lebedev Physical Institute of the Russian Academy of Sciences, 53, Leninsky Ave., 119991 Moscow, Russia
| | - Alexey Yu. Tsvetkov
- V.L. Ginzburg Centre for High-Temperature Superconductivity and Quantum Materials, P.N. Lebedev Physical Institute of the Russian Academy of Sciences, 53, Leninsky Ave., 119991 Moscow, Russia
| | - Lyudmila F. Kulikova
- L.F. Vereshchagin Institute for High Pressure Physics of the Russian Academy of Sciences, 14, Kaluzhskoe Highway, 108840 Moscow, Russia
| | - Alexey S. Medvedev
- V.L. Ginzburg Centre for High-Temperature Superconductivity and Quantum Materials, P.N. Lebedev Physical Institute of the Russian Academy of Sciences, 53, Leninsky Ave., 119991 Moscow, Russia
| | - Kirill S. Pervakov
- V.L. Ginzburg Centre for High-Temperature Superconductivity and Quantum Materials, P.N. Lebedev Physical Institute of the Russian Academy of Sciences, 53, Leninsky Ave., 119991 Moscow, Russia
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4
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Lopes PV, Sundar S, Salem-Sugui S, Hong W, Luo H, Ghivelder L. Second magnetization peak, anomalous field penetration, and Josephson vortices in KCa[Formula: see text]Fe[Formula: see text]As[Formula: see text]F[Formula: see text] bilayer pnictide superconductor. Sci Rep 2022; 12:20359. [PMID: 36437284 PMCID: PMC9701793 DOI: 10.1038/s41598-022-24012-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 11/08/2022] [Indexed: 11/28/2022] Open
Abstract
We performed magnetization measurements in a single crystal of the anisotropic bilayer pnictide superconductor KCa[Formula: see text]Fe[Formula: see text]As[Formula: see text]F[Formula: see text], with [Formula: see text] [Formula: see text] 34 K, for [Formula: see text] [Formula: see text] [Formula: see text]-axis and [Formula: see text] [Formula: see text] [Formula: see text]-planes. A second magnetization peak (SMP) was observed in the isothermal M(H) curves measured below 16 K for [Formula: see text] [Formula: see text] [Formula: see text]-planes. A peak in the temperature variation of the critical current density, [Formula: see text](T), at 16 K, strongly suggests the emergence of Josephson vortices at lower temperatures, which leads to the SMP in the sample. In addition, it is noticed that the appearance of Josephson vortices below 16 K renders easy magnetic flux penetration. A detailed vortex dynamics study suggests that the SMP can be explained in terms of elastic pinning to plastic pinning crossover. Furthermore, contrary to the common understanding, the temperature variation of the first peak field, [Formula: see text], below and above 16 K, behaves non-monotonically. A highly disordered vortex phase, governed by plastic pinning, has been observed between 17 and 23 K, within a field region around an extremely large first peak field. Pinning force scaling suggests that the point defects are the dominant source of pinning for H [Formula: see text] [Formula: see text]-planes, whereas, for H [Formula: see text] [Formula: see text]-axis, point defects in addition to surface defects are at play. Such disorder contributes to the pinning due to the variation in charge carrier mean free path, [Formula: see text] -pinning. Moreover, the large [Formula: see text] observed in our study is consistent with the literature, which advocates this material for high magnetic field applications.
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Affiliation(s)
- P. V. Lopes
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-972 Brazil
| | - Shyam Sundar
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-972 Brazil
- Present Address: School of Physics and Astronomy, University of St. Andrews, St Andrews, KY16 9SS UK
| | - S. Salem-Sugui
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-972 Brazil
| | - Wenshan Hong
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190 China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190 China
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871 China
| | - Huiqian Luo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190 China
- Songshan Lake Materials Laboratory, Dongguan, 523808 Guangdong China
| | - L. Ghivelder
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-972 Brazil
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5
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Ishida S, Kagerbauer D, Holleis S, Iida K, Munakata K, Nakao A, Iyo A, Ogino H, Kawashima K, Eisterer M, Eisaki H. Superconductivity-driven ferromagnetism and spin manipulation using vortices in the magnetic superconductor EuRbFe 4As 4. Proc Natl Acad Sci U S A 2021; 118:e2101101118. [PMID: 34493664 PMCID: PMC8449347 DOI: 10.1073/pnas.2101101118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 08/03/2021] [Indexed: 11/18/2022] Open
Abstract
Magnetic superconductors are specific materials exhibiting two antagonistic phenomena, superconductivity and magnetism, whose mutual interaction induces various emergent phenomena, such as the reentrant superconducting transition associated with the suppression of superconductivity around the magnetic transition temperature (T m), highlighting the impact of magnetism on superconductivity. In this study, we report the experimental observation of the ferromagnetic order induced by superconducting vortices in the high-critical-temperature (high-T c) magnetic superconductor EuRbFe4As4 Although the ground state of the Eu2+ moments in EuRbFe4As4 is helimagnetism below T m, neutron diffraction and magnetization experiments show a ferromagnetic hysteresis of the Eu2+ spin alignment. We demonstrate that the direction of the Eu2+ moments is dominated by the distribution of pinned vortices based on the critical state model. Moreover, we demonstrate the manipulation of spin texture by controlling the direction of superconducting vortices, which can help realize spin manipulation devices using magnetic superconductors.
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Affiliation(s)
- Shigeyuki Ishida
- Research Institute for Advanced Electronics and Photonics, National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8568, Japan;
| | | | | | - Kazuki Iida
- Neutron Science and Technology Center, Comprehensive Research Organization for Science and Society, Tokai 319-1106, Japan
| | - Koji Munakata
- Neutron Science and Technology Center, Comprehensive Research Organization for Science and Society, Tokai 319-1106, Japan
| | - Akiko Nakao
- Neutron Science and Technology Center, Comprehensive Research Organization for Science and Society, Tokai 319-1106, Japan
| | - Akira Iyo
- Research Institute for Advanced Electronics and Photonics, National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8568, Japan
| | - Hiraku Ogino
- Research Institute for Advanced Electronics and Photonics, National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8568, Japan
| | - Kenji Kawashima
- Research & Development Department, IMRA JAPAN CO., LTD., Kariya 448-8650, Japan
| | | | - Hiroshi Eisaki
- Research Institute for Advanced Electronics and Photonics, National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8568, Japan
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6
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Kauffmann-Weiss S, Iida K, Tarantini C, Boll T, Schneider R, Ohmura T, Matsumoto T, Hatano T, Langer M, Meyer S, Jaroszynski J, Gerthsen D, Ikuta H, Holzapfel B, Hänisch J. Microscopic origin of highly enhanced current carrying capabilities of thin NdFeAs(O,F) films. NANOSCALE ADVANCES 2019; 1:3036-3048. [PMID: 36133600 PMCID: PMC9417295 DOI: 10.1039/c9na00147f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 06/03/2019] [Indexed: 06/16/2023]
Abstract
Fe-based superconductors present a large variety of compounds whose physical properties strongly depend on the crystal structure and chemical composition. Among them, the so-called 1111 compounds show the highest critical temperature T c in the bulk form. Here we demonstrate the realization of excellent superconducting properties in NdFeAs(O1-x F x ). We systematically investigated the correlation between the microstructure at the nanoscale and superconductivity in an epitaxial 22 nm NdFeAs(O1-x F x ) thin film on a MgO single crystalline substrate (T c = 44.7 K). Atomic resolution analysis of the microstructure by transmission electron microscopy and atom probe tomography identified several defects and other inhomogeneities at the nanoscale that can act as extrinsic pinning centers. X-Ray diffraction and transmission electron microscopy displayed a broad variation of the a-axis lattice parameter either due to a partially strained layer at the interface to the substrate, high local strain at dislocation arrays, mosaicity, or due to composition variation within the film. The electrical transport properties are substantially affected by intrinsic pinning and a matching field corresponding to the film thickness and associated with the Bean-Livingston surface barrier of the surfaces. The thin film showed a self-field critical current density J c(4.2 K) of ∼7.6 MA cm-2 and a record pinning force density of F p ≈ 1 TN m-3 near 35 T for H‖ab at 4.2 K. These investigations highlight the role of the microstructure in fine-tuning and possibly functionalizing the superconductivity of Fe-based superconductors.
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Affiliation(s)
- Sandra Kauffmann-Weiss
- Institute for Technical Physics (ITEP), Karlsruhe Institute of Technology (KIT) 76344 Eggenstein-Leopoldshafen Germany
| | - Kazumasa Iida
- Department of Materials Physics, Nagoya University Furo-cho, Chikusa-ku Nagoya 464-8603 Japan
- Department of Crystalline Materials Science, Nagoya University Furo-cho, Chikusa-ku Nagoya 464-8603 Japan
| | - Chiara Tarantini
- Applied Superconductivity Center, National High Magnetic Field Laboratory, Florida State University 2031 East Paul Dirac Drive Tallahassee Florida 32310 USA
| | - Torben Boll
- Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology (KIT) 76344 Eggenstein-Leopoldshafen Germany
- Institute for Applied Materials (IAM-WK), Karlsruhe Institute of Technology (KIT) 76344 Karlsruhe Germany
| | - Reinhard Schneider
- Laboratory for Electron Microscopy (LEM), Karlsruhe Institute of Technology (KIT) Engesserstraße 7 76131 Karlsruhe Germany
| | - Taito Ohmura
- Department of Crystalline Materials Science, Nagoya University Furo-cho, Chikusa-ku Nagoya 464-8603 Japan
| | - Takuya Matsumoto
- Department of Materials Physics, Nagoya University Furo-cho, Chikusa-ku Nagoya 464-8603 Japan
| | - Takafumi Hatano
- Department of Materials Physics, Nagoya University Furo-cho, Chikusa-ku Nagoya 464-8603 Japan
- Department of Crystalline Materials Science, Nagoya University Furo-cho, Chikusa-ku Nagoya 464-8603 Japan
| | - Marco Langer
- Institute for Technical Physics (ITEP), Karlsruhe Institute of Technology (KIT) 76344 Eggenstein-Leopoldshafen Germany
| | - Sven Meyer
- Institute for Technical Physics (ITEP), Karlsruhe Institute of Technology (KIT) 76344 Eggenstein-Leopoldshafen Germany
| | - Jan Jaroszynski
- Applied Superconductivity Center, National High Magnetic Field Laboratory, Florida State University 2031 East Paul Dirac Drive Tallahassee Florida 32310 USA
| | - Dagmar Gerthsen
- Laboratory for Electron Microscopy (LEM), Karlsruhe Institute of Technology (KIT) Engesserstraße 7 76131 Karlsruhe Germany
| | - Hiroshi Ikuta
- Department of Materials Physics, Nagoya University Furo-cho, Chikusa-ku Nagoya 464-8603 Japan
- Department of Crystalline Materials Science, Nagoya University Furo-cho, Chikusa-ku Nagoya 464-8603 Japan
| | - Bernhard Holzapfel
- Institute for Technical Physics (ITEP), Karlsruhe Institute of Technology (KIT) 76344 Eggenstein-Leopoldshafen Germany
| | - Jens Hänisch
- Institute for Technical Physics (ITEP), Karlsruhe Institute of Technology (KIT) 76344 Eggenstein-Leopoldshafen Germany
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7
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Eley S, Khilstrom K, Fotovat R, Xiao ZL, Chen A, Chen D, Leroux M, Welp U, Kwok WK, Civale L. Glassy Dynamics in a heavy ion irradiated NbSe 2 crystal. Sci Rep 2018; 8:13162. [PMID: 30177792 PMCID: PMC6120952 DOI: 10.1038/s41598-018-31203-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 08/09/2018] [Indexed: 11/08/2022] Open
Abstract
Fascination with glassy states has persisted since Fisher introduced the vortex-glass as a new thermodynamic phase that is a true superconductor that lacks conventional long-range order. Though Fisher's original model considered point disorder, it was later predicted that columnar defects (CDs) could also induce glassiness - specifically, a Bose-glass phase. In YBa2Cu3O7-x (YBCO), glassy states can cause distinct behavior in the temperature (T ) dependent rate of thermally activated vortex motion (S). The vortex-glass state produces a plateau in S(T ) whereas a Bose-glass can transition into a state hosting vortex excitations called double-kinks that can expand, creating a large peak in S(T ). Although glass phases have been well-studied in YBCO, few studies exist of other materials containing CDs that could contribute to distinguishing universal behavior. Here, we report on the effectiveness of CDs tilted ~30° from the c-axis in reducing S in a NbSe2 crystal. The magnetization is 5 times higher and S is minimized when the field is parallel to the defects versus aligned with the c-axis. We see signatures of glassiness in both field orientations, but do not observe a peak in S(T ) nor a plateau at values observed in YBCO. Finally, we discuss the possibility that competing disorder induces a field-orientation-driven transition from a Bose-glass to an anisotropic glass involving both point and columnar disorder.
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Affiliation(s)
- S Eley
- Condensed Matter and Magnet Science, MPA, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
- Department of Physics, Colorado School of Mines, Golden, CO, 80401, USA
| | - K Khilstrom
- Materials Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - R Fotovat
- Materials Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Z L Xiao
- Materials Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - A Chen
- Center for Integrated Nanotechnology (CINT), MPA, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - D Chen
- Materials Science and Technology Division, MST-8, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - M Leroux
- Condensed Matter and Magnet Science, MPA, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
- Materials Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - U Welp
- Materials Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - W K Kwok
- Materials Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - L Civale
- Condensed Matter and Magnet Science, MPA, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
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8
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Kumar D, Kuo CN, Astuti F, Shang T, Lee MK, Lue CS, Watanabe I, Barker JAT, Shiroka T, Chang LJ. Nodeless superconductivity in the cage-type superconductor Sc 5Ru 6Sn 18 with preserved time-reversal symmetry. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:315803. [PMID: 29947614 DOI: 10.1088/1361-648x/aacf65] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We report the single-crystal synthesis and detailed investigations of the cage-type superconductor Sc5Ru6Sn18, using powder x-ray diffraction (XRD), magnetization, specific-heat and muon-spin relaxation (µSR) measurements. Sc5Ru6Sn18 crystallizes in a tetragonal structure (space group I41/acd) with lattice parameters a = 1.387(3) nm and c = 2.641(5) nm. Both DC and AC magnetization measurements prove the type-II superconductivity in Sc5Ru6Sn18 with T c ≈ 3.5(1) K, a lower critical field [Formula: see text] = 157(9) Oe and an upper critical field, [Formula: see text] = 26(1) kOe. The zero-field electronic specific-heat data are well fitted using a single-gap BCS model, with [Formula: see text] = 0.64(1) meV. The Sommerfeld constant γ varies linearly with the applied magnetic field, indicating s-wave superconductivity in Sc5Ru6Sn18. Specific-heat and transverse-field (TF) µSR measurements reveal that Sc5Ru6Sn18 is a superconductor with strong electron-phonon coupling, with TF-µSR also suggesting a single-gap s-wave character of the superconductivity. Furthermore, zero-field µSR measurements do not detect spontaneous magnetic fields below T c, hence implying that time-reversal symmetry is preserved in Sc5Ru6Sn18.
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Affiliation(s)
- D Kumar
- Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan
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9
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A peak in the critical current for quantum critical superconductors. Nat Commun 2018; 9:434. [PMID: 29382852 PMCID: PMC5789853 DOI: 10.1038/s41467-018-02899-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 01/08/2018] [Indexed: 11/09/2022] Open
Abstract
Generally, studies of the critical current Ic are necessary if superconductors are to be of practical use, because Ic sets the current limit below which there is a zero-resistance state. Here, we report a peak in the pressure dependence of the zero-field Ic, Ic(0), at a hidden quantum critical point (QCP), where a continuous antiferromagnetic transition temperature is suppressed by pressure toward 0 K in CeRhIn5 and 4.4% Sn-doped CeRhIn5. The Ic(0)s of these Ce-based compounds under pressure exhibit a universal temperature dependence, underlining that the peak in zero-field Ic(P) is determined predominantly by critical fluctuations associated with the hidden QCP. The dc conductivity σdc is a minimum at the QCP, showing anti-correlation with Ic(0). These discoveries demonstrate that a quantum critical point hidden inside the superconducting phase in strongly correlated materials can be exposed by the zero-field Ic, therefore providing a direct link between a QCP and unconventional superconductivity.
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10
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Hu Y, Cecconello A, Idili A, Ricci F, Willner I. Triplex DNA Nanostructures: From Basic Properties to Applications. Angew Chem Int Ed Engl 2017; 56:15210-15233. [PMID: 28444822 DOI: 10.1002/anie.201701868] [Citation(s) in RCA: 227] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Indexed: 12/16/2022]
Abstract
Triplex nucleic acids have recently attracted interest as part of the rich "toolbox" of structures used to develop DNA-based nanostructures and materials. This Review addresses the use of DNA triplexes to assemble sensing platforms and molecular switches. Furthermore, the pH-induced, switchable assembly and dissociation of triplex-DNA-bridged nanostructures are presented. Specifically, the aggregation/deaggregation of nanoparticles, the reversible oligomerization of origami tiles and DNA circles, and the use of triplex DNA structures as functional units for the assembly of pH-responsive systems and materials are described. Examples include semiconductor-loaded DNA-stabilized microcapsules, DNA-functionalized dye-loaded metal-organic frameworks (MOFs), and the pH-induced release of the loads. Furthermore, the design of stimuli-responsive DNA-based hydrogels undergoing reversible pH-induced hydrogel-to-solution transitions using triplex nucleic acids is introduced, and the use of triplex DNA to assemble shape-memory hydrogels is discussed. An outlook for possible future applications of triplex nucleic acids is also provided.
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Affiliation(s)
- Yuwei Hu
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - Alessandro Cecconello
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - Andrea Idili
- Department of Chemistry, University of Rome, Tor Vergata, via della Ricerca Scientifica, 00133, Rome, Italy
| | - Francesco Ricci
- Department of Chemistry, University of Rome, Tor Vergata, via della Ricerca Scientifica, 00133, Rome, Italy
| | - Itamar Willner
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
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11
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Hu Y, Cecconello A, Idili A, Ricci F, Willner I. Triplex-DNA-Nanostrukturen: von grundlegenden Eigenschaften zu Anwendungen. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201701868] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Yuwei Hu
- Institute of Chemistry; The Hebrew University of Jerusalem; Jerusalem 91904 Israel
| | | | - Andrea Idili
- Department of Chemistry; Universität Rom; Tor Vergata, via della Ricerca Scientifica 00133 Rom Italien
| | - Francesco Ricci
- Department of Chemistry; Universität Rom; Tor Vergata, via della Ricerca Scientifica 00133 Rom Italien
| | - Itamar Willner
- Institute of Chemistry; The Hebrew University of Jerusalem; Jerusalem 91904 Israel
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12
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Kwok WK, Welp U, Glatz A, Koshelev AE, Kihlstrom KJ, Crabtree GW. Vortices in high-performance high-temperature superconductors. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2016; 79:116501. [PMID: 27652716 DOI: 10.1088/0034-4885/79/11/116501] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The behavior of vortex matter in high-temperature superconductors (HTS) controls the entire electromagnetic response of the material, including its current carrying capacity. Here, we review the basic concepts of vortex pinning and its application to a complex mixed pinning landscape to enhance the critical current and to reduce its anisotropy. We focus on recent scientific advances that have resulted in large enhancements of the in-field critical current in state-of-the-art second generation (2G) YBCO coated conductors and on the prospect of an isotropic, high-critical current superconductor in the iron-based superconductors. Lastly, we discuss an emerging new paradigm of critical current by design-a drive to achieve a quantitative correlation between the observed critical current density and mesoscale mixed pinning landscapes by using realistic input parameters in an innovative and powerful large-scale time dependent Ginzburg-Landau approach to simulating vortex dynamics.
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Affiliation(s)
- Wai-Kwong Kwok
- Materials Science Division, Argonne National Laboratory, Argonne, IL 60439, USA
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13
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Ozaki T, Wu L, Zhang C, Jaroszynski J, Si W, Zhou J, Zhu Y, Li Q. A route for a strong increase of critical current in nanostrained iron-based superconductors. Nat Commun 2016; 7:13036. [PMID: 27708268 PMCID: PMC5059717 DOI: 10.1038/ncomms13036] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 08/29/2016] [Indexed: 11/24/2022] Open
Abstract
The critical temperature Tc and the critical current density Jc determine the limits to large-scale superconductor applications. Superconductivity emerges at Tc. The practical current-carrying capability, measured by Jc, is the ability of defects in superconductors to pin the magnetic vortices, and that may reduce Tc. Simultaneous increase of Tc and Jc in superconductors is desirable but very difficult to realize. Here we demonstrate a route to raise both Tc and Jc together in iron-based superconductors. By using low-energy proton irradiation, we create cascade defects in FeSe0.5Te0.5 films. Tc is enhanced due to the nanoscale compressive strain and proximity effect, whereas Jc is doubled under zero field at 4.2 K through strong vortex pinning by the cascade defects and surrounding nanoscale strain. At 12 K and above 15 T, one order of magnitude of Jc enhancement is achieved in both parallel and perpendicular magnetic fields to the film surface. Simultaneous increase of critical temperature and critical current in superconductors is desirable for application purpose, but very difficult to realize. Here, Ozaki et al. report a simultaneous enhancement of Tc and Jc in FeSe0.5Te0.5 films with cascade defects produced by low-energy proton irradiation.
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Affiliation(s)
- Toshinori Ozaki
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA.,Department of Nanotechnology for Sustainable Energy, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan
| | - Lijun Wu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Cheng Zhang
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Jan Jaroszynski
- National High Magnetic Field Laboratory, Florida State University, 1800 E. Paul Dirac Drive, Tallahassee, Florida 32310, USA
| | - Weidong Si
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Juan Zhou
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Yimei Zhu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Qiang Li
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
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14
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Mishev V, Nakajima M, Eisaki H, Eisterer M. Effects of introducing isotropic artificial defects on the superconducting properties of differently doped Ba-122 based single crystals. Sci Rep 2016; 6:27783. [PMID: 27301665 PMCID: PMC4908418 DOI: 10.1038/srep27783] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 05/23/2016] [Indexed: 11/09/2022] Open
Abstract
The effects of isotropic artifical defects, introduced via fast neutron (E > 0.1 MeV) irradiation, on the physical properties of differently (Co, P and K) doped BaFe2As2 superconducting single crystals were studied. The Co- and P-doped single crystals showed a second peak in the magnetization curve (fishtail effect) in the pristine state. Significant variations in the radiation-induced changes in the critical current density Jc were observed in the different types of crystal, while the irreversibility fields did not change remarkably. The highest Jcs were obtained for the K-doped crystal, exceeding 3 × 10(10) Am(-2) (T = 5 K, B = 4 T) and remaining above 8.5 × 10(9) Am(-2) at 30 K and 1 T. The pinning force was analyzed to compare the pinning mechanisms of the individual samples. While distinct differences were found before the irradiation, the same pinning behavior prevails afterwards. The pinning efficiency η = Jc/Jd was estimated from the depairing current density Jd. η was similar in all irradiated crystals and comparable to the value in neutron irradiated cuprates, suggesting that the huge critical current densities measured in the irradiated K-doped crystal are due to its large depairing current density, making this compound the most promising for applications.
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Affiliation(s)
- V Mishev
- Atominstitut, TU Wien, Stadionallee 2, 1020 Vienna, Austria
| | - M Nakajima
- Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568, Japan
| | - H Eisaki
- Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568, Japan
| | - M Eisterer
- Atominstitut, TU Wien, Stadionallee 2, 1020 Vienna, Austria
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15
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Sadovskyy IA, Jia Y, Leroux M, Kwon J, Hu H, Fang L, Chaparro C, Zhu S, Welp U, Zuo JM, Zhang Y, Nakasaki R, Selvamanickam V, Crabtree GW, Koshelev AE, Glatz A, Kwok WK. Toward Superconducting Critical Current by Design. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:4593-4600. [PMID: 27030115 DOI: 10.1002/adma.201600602] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Revised: 02/09/2016] [Indexed: 06/05/2023]
Abstract
A new critical-current-by-design paradigm is presented. It aims at predicting the optimal defect landscape in superconductors for targeted applications by elucidating the vortex dynamics responsible for the bulk critical current. To this end, critical current measurements on commercial high-temperature superconductors are combined with large-scale time-dependent Ginzburg-Landau simulations of vortex dynamics.
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Affiliation(s)
- Ivan A Sadovskyy
- Materials Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Ying Jia
- Materials Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Maxime Leroux
- Materials Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Jihwan Kwon
- Department of Materials Science and Engineering, University of Illinois-Urbana Champaign, Urbana, IL, 61801, USA
| | - Hefei Hu
- Materials Research Laboratory, University of Illinois-Urbana Champaign, Urbana, IL, 61801, USA
| | - Lei Fang
- Materials Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
- Department of Chemistry, Northwestern University, Evanston, IL, 60208, USA
| | - Carlos Chaparro
- Materials Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Shaofei Zhu
- Physics Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Ulrich Welp
- Materials Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Jian-Min Zuo
- Department of Materials Science and Engineering, University of Illinois-Urbana Champaign, Urbana, IL, 61801, USA
- Materials Research Laboratory, University of Illinois-Urbana Champaign, Urbana, IL, 61801, USA
| | - Yifei Zhang
- SuperPower Corp, Schenectady, NY, 12304, USA
| | | | - Venkat Selvamanickam
- Department of Mechanical Engineering and Texas Center for Superconductivity, University of Houston, Houston, TX, 77204, USA
| | - George W Crabtree
- Materials Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
- Departments of Physics, Electrical and Mechanical Engineering, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Alexei E Koshelev
- Materials Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Andreas Glatz
- Materials Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
- Department of Physics, Northern Illinois University, DeKalb, IL, 60115, USA
| | - Wai-Kwong Kwok
- Materials Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
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16
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Song D, Ishida S, Iyo A, Nakajima M, Shimoyama JI, Eisterer M, Eisaki H. Distinct doping dependence of critical temperature and critical current density in Ba1-xKxFe2As2 superconductor. Sci Rep 2016; 6:26671. [PMID: 27220461 PMCID: PMC4879573 DOI: 10.1038/srep26671] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 05/05/2016] [Indexed: 12/04/2022] Open
Abstract
Since the high transition temperature (High-Tc) superconductivity was discovered in the series of materials containing iron (Fe), their potential for the applications has been extensively scrutinized. In particular, a lot of effort has been made in achieving the high current-carrying ability by revealing the vortex pinning behavior. Here, we report on the critical current density (Jc) for the pristine Ba1-xKxFe2As2 single crystals with various K concentrations (0.25 ≤ x ≤ 0.52) determined by the magnetization hysteresis loop measurements. The x-dependence of Jc is characterized by a spike-like peak at x ~ 0.30, which corresponds to the under-doped region. This behavior is distinct from a moderate Tc dome with a broad maximum spanning from x ~ 0.3 to 0.5. For the under-doped samples, with increasing magnetic field (H), a second magnetization peak in Jc is observed, whereas for the optimally- and over-doped samples, Jc monotonically decreases with H. This result emphasizes that fine tuning of doping composition is important to obtain strong flux pinning. The origin of the characteristic doping dependence of Jc is discussed in connection with the orthorhombic phase domain boundary, as well as the chemical inhomogeneity introduced by the dopant substitutions.
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Affiliation(s)
- Dongjoon Song
- Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8568, Japan
| | - Shigeyuki Ishida
- Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8568, Japan
| | - Akira Iyo
- Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8568, Japan
| | - Masamichi Nakajima
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Jun-ichi Shimoyama
- Department of Physics and Mathematics, Aoyama Gakuin University, Sagamihara 252-5258, Japan
| | - Michael Eisterer
- Atominstitut, Vienna University of Technology, Stadionallee 2, 1020 Vienna, Austria
| | - Hiroshi Eisaki
- Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8568, Japan
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17
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Zhou W, Xing X, Wu W, Zhao H, Shi Z. Second magnetization peak effect, vortex dynamics, and flux pinning in 112-type superconductor Ca0.8La0.2Fe(1-x)CoxAs2. Sci Rep 2016; 6:22278. [PMID: 26947572 PMCID: PMC4780090 DOI: 10.1038/srep22278] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 02/10/2016] [Indexed: 11/30/2022] Open
Abstract
Investigation of vortex pinning and its relaxation is of great importance for both basic physics and technological applications in the field of superconductivity. We report a great improvement of superconducting properties in the recently discovered 112-type superconductors (Ca, La)FeAs2 through Co co-doping. High critical current density Js(5 K) > 2(*)10(6) A/cm(2) is obtained and pronounced second peak effect is observed in magnetization hysteresis loops. Both the dynamic and static relaxation studies result in comparable and sizable relaxation rates S or Q, indicating a fast vortex creep. The second magnetization peak (SMP) is found to be strongly associated with a crossover from elastic to plastic vortex creep. Above the crossover, plastic vortex creep governs the vortex dynamics in a wide range of temperatures and fields. A good scaling behavior of the normalized pinning force density fp by formula fp = h(p)(1-h)(q) ((p) = 1.44, q = 1.66, h = 0.44) is revealed, which demonstrates an important contribution from core normal point-like pinning sites. To better understand the SMP phenomenon, we discuss the related physical scenario as well as the affecting factors in the SMP occurrence.
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Affiliation(s)
- Wei Zhou
- Department of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 211189, China
| | - Xiangzhuo Xing
- Department of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 211189, China
| | - Wenjuan Wu
- Department of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 211189, China
| | - Haijun Zhao
- Department of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 211189, China
| | - Zhixiang Shi
- Department of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 211189, China
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18
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High field superconducting properties of Ba(Fe1-xCox)2As2 thin films. Sci Rep 2015; 5:17363. [PMID: 26612567 PMCID: PMC4661601 DOI: 10.1038/srep17363] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 10/26/2015] [Indexed: 11/09/2022] Open
Abstract
In general, the critical current density, Jc, of type II superconductors and its anisotropy with respect to magnetic field orientation is determined by intrinsic and extrinsic properties. The Fe-based superconductors of the ‘122’ family with their moderate electronic anisotropies and high yet accessible critical fields (Hc2 and Hirr) are a good model system to study this interplay. In this paper, we explore the vortex matter of optimally Co-doped BaFe2As2 thin films with extended planar and c-axis correlated defects. The temperature and angular dependence of the upper critical field is well explained by a two-band model in the clean limit. The dirty band scenario, however, cannot be ruled out completely. Above the irreversibility field, the flux motion is thermally activated, where the activation energy U0 is going to zero at the extrapolated zero-kelvin Hirr value. The anisotropy of the critical current density Jc is both influenced by the Hc2 anisotropy (and therefore by multi-band effects) as well as the extended planar and columnar defects present in the sample.
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19
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Shabbir B, Wang X, Ghorbani SR, Wang AF, Dou S, Chen XH. Giant enhancement in critical current density, up to a hundredfold, in superconducting NaFe0.97Co0.03 As single crystals under hydrostatic pressure. Sci Rep 2015; 5:10606. [PMID: 26030085 PMCID: PMC4649905 DOI: 10.1038/srep10606] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Accepted: 03/27/2015] [Indexed: 11/09/2022] Open
Abstract
Tremendous efforts towards improvement in the critical current density "Jc" of iron based superconductors (FeSCs), especially at relatively low temperatures and magnetic fields, have been made so far through different methods, resulting in real progress. Jc at high temperatures in high fields still needs to be further improved, however, in order to meet the requirements of practical applications. Here, we demonstrate a simple approach to achieve this. Hydrostatic pressure can significantly enhance Jc in NaFe0.97Co0.03As single crystals by at least tenfold at low field and more than a hundredfold at high fields. Significant enhancement in the in-field performance of NaFe0.97Co0.03As single crystal in terms of pinning force density (Fp) is found at high pressures. At high fields, the Fp is over 20 and 80 times higher than under ambient pressure at12 K and 14 K, respectively, at P = 1 GPa. We believe that the Co-doped NaFeAs compounds are very exciting and deserve to be more intensively investigated. Finally, it is worthwhile to say that by using hydrostatic pressure, we can achieve more milestones in terms of high Jc values in tapes, wires or films of other Fe-based superconductors.
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Affiliation(s)
- Babar Shabbir
- Spintronic and Electronic Materials Group, Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, North Wollongong, NSW 2522, Australia
| | - Xiaolin Wang
- Spintronic and Electronic Materials Group, Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, North Wollongong, NSW 2522, Australia
| | - S R Ghorbani
- 1] Spintronic and Electronic Materials Group, Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, North Wollongong, NSW 2522, Australia [2] Department of Physics, Ferdowsi University of Mashhad, Mashhad 9177948974, Iran
| | - A F Wang
- Department of Physics, University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Shixue Dou
- Spintronic and Electronic Materials Group, Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, North Wollongong, NSW 2522, Australia
| | - X H Chen
- Department of Physics, University of Science and Technology of China, Hefei, 230026, P. R. China
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20
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Massee F, Sprau PO, Wang YL, Davis JCS, Ghigo G, Gu GD, Kwok WK. Imaging atomic-scale effects of high-energy ion irradiation on superconductivity and vortex pinning in Fe(Se,Te). SCIENCE ADVANCES 2015; 1:e1500033. [PMID: 26601180 PMCID: PMC4640636 DOI: 10.1126/sciadv.1500033] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 04/13/2015] [Indexed: 05/05/2023]
Abstract
Maximizing the sustainable supercurrent density, J C, is crucial to high-current applications of superconductivity. To achieve this, preventing dissipative motion of quantized vortices is key. Irradiation of superconductors with high-energy heavy ions can be used to create nanoscale defects that act as deep pinning potentials for vortices. This approach holds unique promise for high-current applications of iron-based superconductors because J C amplification persists to much higher radiation doses than in cuprate superconductors without significantly altering the superconducting critical temperature. However, for these compounds, virtually nothing is known about the atomic-scale interplay of the crystal damage from the high-energy ions, the superconducting order parameter, and the vortex pinning processes. We visualize the atomic-scale effects of irradiating FeSe x Te1-x with 249-MeV Au ions and find two distinct effects: compact nanometer-sized regions of crystal disruption or "columnar defects," plus a higher density of single atomic site "point" defects probably from secondary scattering. We directly show that the superconducting order is virtually annihilated within the former and suppressed by the latter. Simultaneous atomically resolved images of the columnar crystal defects, the superconductivity, and the vortex configurations then reveal how a mixed pinning landscape is created, with the strongest vortex pinning occurring at metallic core columnar defects and secondary pinning at clusters of point-like defects, followed by collective pinning at higher fields.
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Affiliation(s)
- Freek Massee
- Condensed Matter Physics & Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973, USA
- Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, NY 14853, USA
- Laboratoire de Physique des Solides, Universite Paris-Sud, 91405 Orsay, France
- Corresponding author. E-mail:
| | - Peter Oliver Sprau
- Condensed Matter Physics & Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973, USA
- Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, NY 14853, USA
| | - Yong-Lei Wang
- Materials Science Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - J. C. Séamus Davis
- Condensed Matter Physics & Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973, USA
- Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, NY 14853, USA
- School of Physics and Astronomy, University of St Andrews, St Andrews, Fife KY16 9SS, UK
- Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, NY 14853, USA
| | - Gianluca Ghigo
- Department of Applied Science and Technology, Politecnico di Torino, 10129 Torino, Italy
- Istituto Nazionale di Fisica Nucleare, Sezione di Torino, 10125 Torino, Italy
| | - Genda D. Gu
- Condensed Matter Physics & Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Wai-Kwong Kwok
- Materials Science Division, Argonne National Laboratory, Argonne, IL 60439, USA
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21
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Hydrostatic pressure: a very effective approach to significantly enhance critical current density in granular iron pnictide superconductors. Sci Rep 2015; 5:8213. [PMID: 25645351 PMCID: PMC4314637 DOI: 10.1038/srep08213] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 12/16/2014] [Indexed: 12/04/2022] Open
Abstract
Pressure is well known to significantly raise the superconducting transition temperature, Tc, in both iron pnictides and cuprate based superconductors. Little work has been done, however, on how pressure can affect the flux pinning and critical current density in the Fe-based superconductors. Here, we propose to use hydrostatic pressure to significantly enhance flux pinning and Tc in polycrystalline pnictide bulks. We have chosen Sr4V2O6Fe2As2 polycrystalline samples as a case study. We demonstrate that the hydrostatic pressure up to 1.2 GPa can not only significantly increase Tc from 15 K (underdoped) to 22 K, but also significantly enhance the irreversibility field, Hirr, by a factor of 4 at 7 K, as well as the critical current density, Jc, by up to 30 times at both low and high fields. It was found that pressure can induce more point defects, which are mainly responsible for the Jc enhancement. Our findings provide an effective method to significantly enhance Tc, Jc, Hirr, and the upper critical field, Hc2, for other families of Fe-based superconductors in the forms of wires/tapes, films, and single crystal and polycrystalline bulks.
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22
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Embon L, Anahory Y, Suhov A, Halbertal D, Cuppens J, Yakovenko A, Uri A, Myasoedov Y, Rappaport ML, Huber ME, Gurevich A, Zeldov E. Probing dynamics and pinning of single vortices in superconductors at nanometer scales. Sci Rep 2015; 5:7598. [PMID: 25564043 PMCID: PMC4288220 DOI: 10.1038/srep07598] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 12/03/2014] [Indexed: 11/08/2022] Open
Abstract
The dynamics of quantized magnetic vortices and their pinning by materials defects determine electromagnetic properties of superconductors, particularly their ability to carry non-dissipative currents. Despite recent advances in the understanding of the complex physics of vortex matter, the behavior of vortices driven by current through a multi-scale potential of the actual materials defects is still not well understood, mostly due to the scarcity of appropriate experimental tools capable of tracing vortex trajectories on nanometer scales. Using a novel scanning superconducting quantum interference microscope we report here an investigation of controlled dynamics of vortices in lead films with sub-Angstrom spatial resolution and unprecedented sensitivity. We measured, for the first time, the fundamental dependence of the elementary pinning force of multiple defects on the vortex displacement, revealing a far more complex behavior than has previously been recognized, including striking spring softening and broken-spring depinning, as well as spontaneous hysteretic switching between cellular vortex trajectories. Our results indicate the importance of thermal fluctuations even at 4.2 K and of the vital role of ripples in the pinning potential, giving new insights into the mechanisms of magnetic relaxation and electromagnetic response of superconductors.
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Affiliation(s)
- L. Embon
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Y. Anahory
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - A. Suhov
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - D. Halbertal
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - J. Cuppens
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - A. Yakovenko
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - A. Uri
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Y. Myasoedov
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - M. L. Rappaport
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - M. E. Huber
- Department of Physics, University of Colorado Denver, Denver, 80217, USA
| | - A. Gurevich
- Department of Physics, Old Dominion University, Norfolk, VA 23529-0116, USA
| | - E. Zeldov
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel
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