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Author Aragón Sánchez, J.; Cortés Maldonado, R.; Dolz, M.I.; CejasBolecek, N.R.; van der Beek, C.J.; Konczykowski, M.; Fasano, Y.
Title Direct visualization of local interaction forces in Bi2Sr2CaCu2O8+δ vortex matter Type Journal Article
Year 2019 Publication Materials Today: Proceedings Abbreviated Journal XXIII Latin American Symposium on Solid State Physics (SLAFES XXIII), San Carlos de Bariloche, Argen
Volume 14 Issue Pages 34-37
Keywords Vortex matter; Pinning forces; Layered superconductors
Abstract We study the local vortex-vortex interaction force fi of the structure frozen during a field-cooling process in an electron-irradiated Bi2Sr2CaCu2O8+δ sample. We compute this magnitude from snapshots of the vortex structure obtained via magnetic decoration experiments at various fields H in the same sample. Since the observed structures correspond to the equilibrium ones frozen at T∼Tirr(H)[1], at this temperature the local modulus of fi roughly equals the local pinning force at the decorated surface of the sample. We estimate the most probable local pinning force from the mode value of the fi(r)distribution, fpm. We found that fpm grows algebraically with H and in electron-irradiated samples is 50-20% smaller than for samples with columnar defects.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2214-7853 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ pedrazp @ Serial 852
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Author Cejas Bolecek, N.R.; Dolz, M.I.; Kolton, A.; Pastoriza, H.; Beek, C.Jvander; Konczykowski, M.; Menghini, M.; Nieva, G.; Fasano, Y.
Title Geometrical Confinement Effects in Layered Mesoscopic Vortex Matter Type Journal Article
Year 2015 Publication Journal of Low Temperature Physics Abbreviated Journal J. Low Temp. Phys.
Volume 179 Issue 1-2 Pages 35-41
Keywords Vortex matter; Mesoscopic physics; Layered superconductors
Abstract We study the geometrical confinement effect in Bi 2 Sr 2 CaCu 2 O 8+δ mesoscopic vortex matter with edge-to-surface ratio of 7–12 %. Samples have in-plane square and circular edges, 30 μ m widths, and ∼ 2 μ m thickness. Direct vortex imaging reveals the compact planes of the structure align with the sample edge by introducing topological defects. The defect density is larger for circular than for square edges. Molecular dynamics simulations suggest that this density is not an out-of-equilibrium property but rather determined by the geometrical confinement.
Address
Corporate Author Thesis
Publisher Springer US Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-2291 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ pedrazp @ Serial 711
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Author Puig, J.; Cejas Bolecek, N.R.; Aragón Sánchez, J.; Dolz, M.I.; Konczykowski, M.; Fasano, Y.
Title Bridge in micron-sized Bi2Sr2CaCu2O8 sample act as converging lens for vortices Type Journal Article
Year 2021 Publication Physica C: Superconductivity and its Applications Abbreviated Journal Physica C
Volume 590 Issue Pages 1353948
Keywords Vortex matterMesoscopic samplesStructural properties
Abstract We report on direct imaging of vortex matter nucleated in micron-sized BiSrCaCuO superconducting samples that incidentally present a bridge structure. We find that when nucleating vortices in a field-cooling condition the deck of the bridge acts as a converging lens for vortices. By means of Bitter decoration images allowing us to quantify the enhancement of vortex-vortex interaction energy per unit length in the deck of the bridge, we are able to estimate that the deck is thinner than m. We show that the structural properties of vortex matter nucleated in micron-sized thin samples are not significantly affected by sample-thickness variations of the order of half a micron, an important information for type-II superconductors-based mesoscopic technological devices.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0921-4534 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ pedrazp @ Serial 878
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Author Rumi, G.; Albornoz, L.J.; Pedrazzini, P.; Dolz, M.I.; Pastoriza, H.; van der Beek, C.J.; Konczykowski, M.; Fasano, Y.
Title Entropy jump at the first-order vortex phase transition in Bi2Sr2CaCu2O8+δ with columnar defects Type Journal Article
Year 2019 Publication Materials Today: Proceedings Abbreviated Journal XXIII Latin American Symposium on Solid State Physics (SLAFES XXIII), San Carlos de Bariloche, Argen
Volume 14 Issue Pages 30-33
Keywords vortex matter; first-order melting transition; high-temperature superconductivity; correlated disorder
Abstract We study the entropy jump associated with the first-order vortex melting transition (FOT) in Bi2Sr2CaCu2O8+δ crystals by means of Hall probe magnetometry. The samples present a diluted distribution of columnar defects (CD) introduced by irradiation with Xe ions. The FOT is detected in ac transmittivity measurements as a paramagnetic peak, the height of which is proportional to the enthalpy difference entailed by the transition. By applying the Clausius-Clapeyron relation, we quantify the evolution of the entropy jump Δs as a function of the FOT temperature, TFOT, in both pristine crystals and crystals with CD. On increasing the density of CD, Δs decreases monotonically with respect to values found in pristine samples. The Δs versus TFOT dependence in the case of pristine samples follows reasonably well the theoretical prediction of dominant electromagnetic coupling for a model neglecting the effect of disorder. The data for samples with a diluted distribution of CD are not properly described by such a theoretical model.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2214-7853 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ pedrazp @ Serial 853
Permanent link to this record