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Author Kapra, A.V.; Vodolazov, D.Y.; Misko, V.R.
Title (up) Vortex transport in a channel with periodic constrictions Type A1 Journal article
Year 2013 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech
Volume 26 Issue 9 Pages 095010-95011
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract By numerically solving the time-dependent Ginzburg-Landau equations in a type-II superconductor, characterized by a critical temperature T-c1, and the coherence length xi(1), with a channel formed by overlapping rhombuses (diamond-like channel) made of another type-II superconductor, characterized, in general, by different T-c2 and xi(2), we investigate the dynamics of driven vortex matter for varying parameters of the channel: the width of the neck connecting the diamond cells, the cell geometry, and the ratio between the coherence lengths in the bank and the channel. We analyzed samples with periodic boundary conditions (which we call 'infinite' samples) and finite-size samples (with boundaries for vortex entry/exit), and we found that by tuning the channel parameters, one can manipulate the vortex dynamics, e.g., change the transition from flux-pinned to flux-flow regime and tune the slope of the IV-curves. In addition, we analyzed the effect of interstitial vortices on these characteristics. The critical current of this device was studied as a function of the applied magnetic field, j(c)(H). The function j(c)(H) reveals a striking commensurability peak, in agreement with recent experimental observations. The obtained results suggest that the diamond channel, which combines the properties of pinning arrays and flux-guiding channels, can be a promising candidate for potential use in devices controlling magnetic flux motion.
Address
Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos 000323073800016 Publication Date 2013-07-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-2048;1361-6668; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.878 Times cited 2 Open Access
Notes ; This work was supported by the 'Odysseus' Program of the Flemish Government and the Flemish Science Foundation (FWO-Vl). ; Approved Most recent IF: 2.878; 2013 IF: 2.796
Call Number UA @ lucian @ c:irua:110737 Serial 3898
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Author Tafuri, F.; Carillo, F.; Lombardi, F.; Granozio, F.M.; dii Uccio, U.S.; Testa, G.; Sarnelli, E.; Verbist, K.; Van Tendeloo, G.
Title (up) YBa2Cu3O7-x Josephson junctions and dc SQUIDs based on 45\text{\textdegree} a-axis tilt and twist grain boundaries : atomically clean interfaces for applications Type A1 Journal article
Year 1999 Publication Superconductor science and technology T2 – International Superconductive Electronics Conference, JUN 21-25, 1999, BERKELEY, CALIFORNIA Abbreviated Journal Supercond Sci Tech
Volume 12 Issue 11 Pages 1007-1009
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract YBa2Cu3O7-x artificial grain boundary Josephson junctions have been fabricated, employing a recently implemented biepitaxial technique. The grain boundaries can be obtained by controlling the orientation of the MgO seed layer and are characterized by a misalignment of the c-axes (45 degrees a-axis tilt or 45 degrees a-axis twist). These types of grain boundaries are still mostly unexplored. We carried out a complete characterization of their transport properties and microstructure. Junctions and de SQUIDs associated with these grain boundaries exhibit an excellent Josephson phenomenology and high values of the ICRN product and of the magnetic flux-to-voltage transfer parameter respectively. Remarkable differences in the transport parameters of tilt and twist junctions have been observed, which can be of interest for several applications. A maximum speed of Josephson vortices as calculated from the voltage step values of the order of 2 x 10(6) m s(-1) is obtained. These devices could also have some impact on experiments designed to study the symmetry of the order parameter, exploiting their microstructure and anisotropic properties. High-resolution electron microscopy showed the presence of perfect basal plane faced boundaries in the cross sections of tilt boundaries.
Address
Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos 000083948400093 Publication Date 2002-08-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-2048;1361-6668; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.878 Times cited 3 Open Access
Notes Approved Most recent IF: 2.878; 1999 IF: 1.728
Call Number UA @ lucian @ c:irua:102896 Serial 3565
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Author Celentano, G.; Rizzo, F.; Augieri, A.; Mancini, A.; Pinto, V.; Rufoloni, A.; Vannozzi, A.; MacManus-Driscoll, J.L.; Feighan, J.; Kursumovic, A.; Meledin, A.; Mayer, J.; Van Tendeloo, G.
Title (up) YBa2Cu3O7−xfilms with Ba2Y(Nb,Ta)O6nanoinclusions for high-field applications Type A1 Journal article
Year 2020 Publication Superconductor Science & Technology Abbreviated Journal Supercond Sci Tech
Volume 33 Issue 4 Pages 044010
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The structural and transport properties of YBa2Cu3O7−x films grown by pulsed laser deposition with mixed 2.5 mol% Ba2YTaO6 (BYTO) and 2.5 mol% Ba2YNbO6 (BYNO) double-perovskite secondary phases are investigated in an extended film growth rate, R = 0.02–1.8 nm s−1. The effect of R on the film microstructure analyzed by TEM techniques shows an evolution from sparse and straight to denser, thinner and splayed continuous columns, with mixed BYNO + BYTO (BYNTO) composition, as R increases from 0.02 nm s−1 to 1.2 nm s−1. This microstructure results in very efficient flux pinning at 77 K, leading to a remarkable improvement in the critical current density (J c) behaviour, with the maximum pinning force density F p(Max) = 13.5 GN m−3 and the irreversibility field in excess of 11 T. In this range, the magnetic field values at which the F p is maximized varies from 1 T to 5 T, being related to the BYNTO columnar density. The film deposited when R = 0.3 nm s−1 exhibits the best performances over the whole temperature and magnetic field ranges, achieving F p(Max) = 900 GN m−3 at 10 K and 12 T. At higher rates, R > 1.2 nm s−1, BYNTO columns show a meandering nature and are prone to form short nanorods. In addition, in the YBCO film matrix a more disordered structure with a high density of short stacking faults is observed. From the analysis of the F p(H, T) curves it emerges that in films deposited at the high R limit, the vortex pinning is no longer dominated by BYNTO columnar defects, but by a new mechanism showing the typical temperature scaling law. Even though this microstructure produces a limited improvement at 77 K, it exhibits a strong J c improvement at lower temperature with F p = 700 GN m−3 at 10 K, 12 T and 900 GN m−3 at 4.2 K, 18 T.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000525650500001 Publication Date 2020-04-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-2048 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.6 Times cited Open Access OpenAccess
Notes This work was partially financially supported by EUROTAPES, a collaborative project funded by the European Commission’s Seventh Framework Program (FP7/2007–2013) under Grant Agreement No. 280432. This work has been partially carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom programme 2014-2018 and 2019-2020 under grant agreement N° 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 823717 – ESTEEM3 (Nano-engineered YBCO Superconducting Tapes for High Field Applications, NESTApp). G. C. acknowledges the support of Michele De Angelis for XRD measurements and calculations. Approved Most recent IF: 3.6; 2020 IF: 2.878
Call Number UA @ lucian @c:irua:168582 Serial 6394
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