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Sundar S, Lopes PV, Salem-Sugui S, Li ZZ, Hong WS, Luo HQ, Li SL, Ghivelder L. Order-disorder phase transition and elastic-to-plastic vortex creep crossover in a triclinic iron pnictide superconductor (Ca[Formula: see text]La[Formula: see text])[Formula: see text](Pt[Formula: see text]As[Formula: see text])(Fe[Formula: see text]As[Formula: see text])[Formula: see text]. Sci Rep 2023; 13:16273. [PMID: 37770517 PMCID: PMC10539531 DOI: 10.1038/s41598-023-43424-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: 06/28/2023] [Accepted: 09/23/2023] [Indexed: 09/30/2023] Open
Abstract
Vortex matter in layered high-[Formula: see text] superconductors, including iron-pnictides, undergo several thermodynamic phase transitions due to the complex interplay of pinning energy, thermal energy and elastic energy. Moreover, the presence of anisotropy makes their vortex physics even more intriguing. Here, we report a detailed vortex dynamics study, using dc magnetization measurements, in a triclinic iron-pnictide superconductor (Ca[Formula: see text]La[Formula: see text])[Formula: see text](Pt[Formula: see text]As[Formula: see text])(Fe[Formula: see text]As[Formula: see text])[Formula: see text], with a superconducting transition temperature, T[Formula: see text] [Formula: see text] 31 K. A second magnetization peak (SMP) feature is observed for magnetic field perpendicular (H[Formula: see text]c) and parallel (H[Formula: see text]ab) to the crystal plane. However, its fundamental origin is quite different in both directions. For H[Formula: see text]c, the SMP can be well explained using an elastic-to-plastic vortex creep crossover, using collective creep theory. In addition, a possible rhombic-to-square vortex lattice phase transition is also observed for fields in between the onset-field and peak-field related to the SMP. On the other hand, for H[Formula: see text]ab, a clear signature of an order-disorder vortex phase transition is observed in the isothermal M(H) measurements at T [Formula: see text] 6 K. The disordered phase exhibits the characteristics of entangled pinned vortex-liquid. We construct a comprehensive vortex phase diagram by displaying characteristic temperatures and magnetic fields for both crystal geometries in this unique superconducting compound. Our study sheds light on the intricate vortex dynamics and pinning in an iron-pnictide superconductor with triclinic symmetry.
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Affiliation(s)
- Shyam Sundar
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-972 Brazil
- School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS Scotland, UK
| | - P. V. Lopes
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-972 Brazil
| | - S. Salem-Sugui
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-972 Brazil
| | - Z.-Z. Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190 China
| | - W.-S. Hong
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190 China
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871 China
| | - H.-Q. Luo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190 China
| | - S.-L. Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190 China
| | - L. Ghivelder
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-972 Brazil
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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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Magnetic Instabilities in the Quasi-One-Dimensional K2Cr3As3 Material with Twisted Triangular Tubes. MATERIALS 2022; 15:ma15062292. [PMID: 35329743 PMCID: PMC8954554 DOI: 10.3390/ma15062292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 03/14/2022] [Accepted: 03/17/2022] [Indexed: 11/16/2022]
Abstract
The magnetic response of a frustrated K2Cr3As3 sample having triangular arrays of twisted tubes has been studied by means of dc magnetization measurements as a function of the magnetic field (H) at different temperatures ranging from 5 K up to 300 K. Looking at the magnetic hysteresis loops m(H), a diamagnetic behavior of the sample was inferred at temperatures higher than 60 K, whereas at lower temperatures the sample showed a hysteresis loop compatible with the presence of ferrimagnetism. Moreover, spike-like magnetization jumps, both positive and negative, were observed in a narrow range of the magnetic field around 800 Oe, regardless of the temperature considered and they were compared with the theoretical predictions on frustrated systems. The field position of the magnetization jumps was studied at different temperatures, and their distribution can be described by a Lorentzian curve. The analogies between the expected features and the experimental observations suggest that the jumps could be attributed to the magnetic frustration arising from the twisted triangular tubes present in the crystal lattice of this compound.
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Galluzzi A, Leo A, Masi A, Varsano F, Nigro A, Grimaldi G, Polichetti M. Critical Current and Pinning Features of a CaKFe 4As 4 Polycrystalline Sample. MATERIALS (BASEL, SWITZERLAND) 2021; 14:6611. [PMID: 34772137 PMCID: PMC8585420 DOI: 10.3390/ma14216611] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 10/29/2021] [Accepted: 11/01/2021] [Indexed: 12/03/2022]
Abstract
We analyze the magnetic behavior of a CaKFe4As4 polycrystalline sample fabricated by a mechanochemically assisted synthesis route. By means of DC magnetization (M) measurements as a function of the temperature (T) and DC magnetic field (H) we study its critical parameters and pinning features. The critical temperature Tc has been evaluated by M(T) curves performed in Zero Field Cooling-Field Cooling conditions. These curves show the presence of a little magnetic background for temperatures above Tc, as also confirmed by the hysteresis loops M(H). Starting from the M(H) curves, the critical current density Jc of the sample has been calculated as a function of the field at different temperatures in the framework of the Bean critical state model. The Jc(H) values are in line with the ones reported in the literature for this typology of samples. By analyzing the temperature dependence of the critical current density Jc(T) at different magnetic fields, it has been found that the sample is characterized by a strong type pinning regime. This sample peculiarity can open perspectives for future improvement in the fabrication of this material.
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Affiliation(s)
- Armando Galluzzi
- Department of Physics “E.R. Caianiello”, University of Salerno, Via Giovanni Paolo II 132, Fisciano, I-84084 Salerno, Italy; (A.L.); (A.N.)
- CNR-SPIN Salerno, Via Giovanni Paolo II 132, Fisciano, I-84084 Salerno, Italy;
| | - Antonio Leo
- Department of Physics “E.R. Caianiello”, University of Salerno, Via Giovanni Paolo II 132, Fisciano, I-84084 Salerno, Italy; (A.L.); (A.N.)
- CNR-SPIN Salerno, Via Giovanni Paolo II 132, Fisciano, I-84084 Salerno, Italy;
| | - Andrea Masi
- ENEA, Via Anguillarese 301, I-00123 Roma, Italy; (A.M.); (F.V.)
- Dipartimento di Ingegneria, Università degli Studi Roma Tre, Via Vito Volterra 62, I-00146 Roma, Italy
| | | | - Angela Nigro
- Department of Physics “E.R. Caianiello”, University of Salerno, Via Giovanni Paolo II 132, Fisciano, I-84084 Salerno, Italy; (A.L.); (A.N.)
- CNR-SPIN Salerno, Via Giovanni Paolo II 132, Fisciano, I-84084 Salerno, Italy;
| | - Gaia Grimaldi
- CNR-SPIN Salerno, Via Giovanni Paolo II 132, Fisciano, I-84084 Salerno, Italy;
| | - Massimiliano Polichetti
- Department of Physics “E.R. Caianiello”, University of Salerno, Via Giovanni Paolo II 132, Fisciano, I-84084 Salerno, Italy; (A.L.); (A.N.)
- CNR-SPIN Salerno, Via Giovanni Paolo II 132, Fisciano, I-84084 Salerno, Italy;
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Galluzzi A, Buchkov K, Tomov V, Nazarova E, Leo A, Grimaldi G, Polichetti M. High Pinning Force Values of a Fe(Se, Te) Single Crystal Presenting a Second Magnetization Peak Phenomenon. MATERIALS 2021; 14:ma14185214. [PMID: 34576443 PMCID: PMC8465423 DOI: 10.3390/ma14185214] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 09/02/2021] [Accepted: 09/07/2021] [Indexed: 11/16/2022]
Abstract
The magnetization M of an Fe(Se, Te) single crystal has been measured as a function of temperature T and dc magnetic field H. The sample properties have been analyzed in the case of a magnetic field parallel to its largest face H||ab. From the M(T) measurement, the Tc of the sample and a magnetic background have been revealed. The superconducting hysteresis loops M(H) were between 2.5 K and 15 K showing a tilt due to the presence of a magnetic signal measured at T > Tc. From the M(H) curves, the critical current density Jc(H) has been extracted at different temperatures showing the presence of a second magnetization peak phenomenon. By extracting and fitting the Jc(T) curves at different fields, a pinning regime crossover has been identified and shown to be responsible for the origin of the second magnetization peak phenomenon. Then, the different kinds of pinning centers of the sample were investigated by means of Dew-Hughes analysis, showing that the pinning mechanism in the sample can be described in the framework of the collective pinning theory. Finally, the values of the pinning force density have been calculated at different temperatures and compared with the literature in order to understand if the sample is promising for high-current and high-power applications.
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Affiliation(s)
- Armando Galluzzi
- Department of Physics “E.R. Caianiello”, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy;
- CNR-SPIN Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy;
- Correspondence: (A.G.); (M.P.)
| | - Krastyo Buchkov
- Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee Blvd., 1784 Sofia, Bulgaria; (K.B.); (V.T.); (E.N.)
- Institute of Optical Materials and Technologies, Bulgarian Academy of Sciences, Acad. G. Bonchev Str. Bl. 109, 1113 Sofia, Bulgaria
| | - Vihren Tomov
- Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee Blvd., 1784 Sofia, Bulgaria; (K.B.); (V.T.); (E.N.)
| | - Elena Nazarova
- Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee Blvd., 1784 Sofia, Bulgaria; (K.B.); (V.T.); (E.N.)
| | - Antonio Leo
- Department of Physics “E.R. Caianiello”, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy;
- CNR-SPIN Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy;
| | - Gaia Grimaldi
- CNR-SPIN Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy;
| | - Massimiliano Polichetti
- Department of Physics “E.R. Caianiello”, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy;
- CNR-SPIN Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy;
- Correspondence: (A.G.); (M.P.)
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Douma BC, Abderezzak B, Ailam E, Felseghi RA, Filote C, Dumitrescu C, Raboaca MS. Design Development and Analysis of a Partially Superconducting Axial Flux Motor Using YBCO Bulks. MATERIALS 2021; 14:ma14154295. [PMID: 34361487 PMCID: PMC8347325 DOI: 10.3390/ma14154295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 07/24/2021] [Accepted: 07/25/2021] [Indexed: 11/16/2022]
Abstract
In this work, authors have designed, constructed and tested a new kind of partially superconducting axial flux machine. This model is based on the magnetic flux concentration principle. The magnetic field creation part consists of the NbTi superconducting solenoid and two YBaCuO plates. A theoretical study is conducted of an extrapolated superconducting inductor for low-temperature superconducting and high-temperature superconducting solenoids. The optimization of the inductor is carried out in order to increase the torque and the power density as well. This improvement is done by changing the shape of the elements which form the superconducting inductor. Finally, a prototype is realized, and tested.
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Affiliation(s)
- Brahim Chelarem Douma
- Laboratoire de l’Énergie et des Systèmes Intelligent (LESI), University of Khemis Miliana, Road of Theniet el Had, Khemis Miliana 44225, Algeria; (B.C.D.); (B.A.); (E.A.)
| | - Bilal Abderezzak
- Laboratoire de l’Énergie et des Systèmes Intelligent (LESI), University of Khemis Miliana, Road of Theniet el Had, Khemis Miliana 44225, Algeria; (B.C.D.); (B.A.); (E.A.)
| | - Elhadj Ailam
- Laboratoire de l’Énergie et des Systèmes Intelligent (LESI), University of Khemis Miliana, Road of Theniet el Had, Khemis Miliana 44225, Algeria; (B.C.D.); (B.A.); (E.A.)
| | - Raluca-Andreea Felseghi
- Faculty of Electrical Engineering and Computer Science, Ștefan cel Mare University of Suceava, Universităţii Street, No.13, 720229 Suceava, Romania; (R.-A.F.); (M.S.R.)
| | - Constantin Filote
- Faculty of Electrical Engineering and Computer Science, Ștefan cel Mare University of Suceava, Universităţii Street, No.13, 720229 Suceava, Romania; (R.-A.F.); (M.S.R.)
- Correspondence:
| | - Catalin Dumitrescu
- National Department Telematics and Electronics for Transports, University “Politehnica” of Bucharest, 060042 Bucharest, Romania;
| | - Maria Simona Raboaca
- Faculty of Electrical Engineering and Computer Science, Ștefan cel Mare University of Suceava, Universităţii Street, No.13, 720229 Suceava, Romania; (R.-A.F.); (M.S.R.)
- National Research and Development Institute for Cryogenic and Isotopic Technologies—ICSI Rm. Valcea, Uzinei Street, No. 4, P.O. Box 7 Raureni, 240050 Valcea, Romania
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