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Author (down) de la Cruz, F.
Title Structural relaxation: low temperature properties Type Conference Article
Year 1984 Publication Abbreviated Journal
Volume Issue Pages 269
Keywords ALLOY SYSTEMS, AMORPHOUS STATE, COPPER ALLOYS, SUPERCONDUCTING COMPOSITES, TEMPERATURE DEPENDENCE, ZIRCONIUM BASE ALLOYS
Abstract We discuss the changes in transport and superconducting properties of amorphous Zr70Cu30,

induced by thermal relaxation The experimental results are used to investigate the

relation between the microscopic parameters and the observed physical properties It

is shown that the density of eletronic states determines the shift Tc as well as the

variation of the electrical resistivity It is necessary to assume strong hybridization

between s and d bands to understand the eletrodynamic response of the superconductor

(Author)
Address
Corporate Author Thesis
Publisher Place of Publication Brazil Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title Proceedings of the Latin American Symposium of Physics of Amorphous Systems – v1
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ pedrazp @ Serial 813
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Author (down) Cotignola, J.M.; de la Cruz, F.; de la Cruz, M.E.; Platzeck, R.P.
Title Thermal Conductivity of Polycrystalline Zinc below 1 K Type Journal Article
Year 1967 Publication Review of Scientific Instruments Abbreviated Journal
Volume 38 Issue 1 Pages 87-92
Keywords
Abstract Measurements of the thermal conductivity of samples of polycrystalline zinc of thickness 0.1 mm have been carried out between 0.12 and 0.9°K in the normal as well as in the superconducting state to investigate the usefulness of zinc as a thermal switch. The conductivity in the normal state shows a linear dependence on temperature. In the superconducting state it shows a behavior typical of electronic conductivity down to the lowest temperature measured. By applying a magnetic field between 40 and 5000 Oe, magnetoresistivity was also investigated and a strong dependence of thermal conductivity on field was found. Electrical resistivity measurements were performed in magnetic fields at liquid 4He temperatures. The resistivity was found to be independent of temperature for fields up to 9000 Oe. The effect of solder joints using Cd, Sn, In, Zn, and Wood's metal was also investigated, Cd giving the least resistance. The measurements show that zinc should be a useful thermal switch for temperatures below 0.1 and 0.2°K, though effect of a magnetic field on the normal conductivity must be carefully considered.
Address Centro Atómico Bariloche – Instituto Balseiro
Corporate Author Thesis
Publisher AIP Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ pedrazp @ cotignola:87 Serial 533
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Author (down) Correa, V.F.; Nieva, G.; Pastoriza, H.; de la Cruz, F.
Title The true pinning force range in Bi2Sr2CaCu2O8 single crystals at low temperatures Type Journal Article
Year 2004 Publication Physica C Abbreviated Journal
Volume 408-410 Issue Pages 531-532
Keywords
Abstract We study the effective profile of the pinning potential well in Bi$2$Sr$2$CaCu$_2$O8+δ single crystals using transverse ac magnetic susceptibility. The results show that the harmonic approximation for the potential well (linear regime) is valid up to vortex displacements $r\simeqξ$, where ξ, is the coherence length. In spite of this, it is necessary to induce displacements of the vortex structure much larger than ξ to depin it from its potential. This is shown to take place even in the single vortex limit.
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 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ hernan @ correa04 Serial 9
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Author (down) Correa, V.F.; Nieva, G.; de la Cruz, F.
Title Vortex softening: Origin of the second peak effect in Bi2Sr2CaCu2O8+delta Type Journal Article
Year 2001 Publication PHYSICAL REVIEW LETTERS Abbreviated Journal
Volume 87 Issue 5 Pages 057003
Keywords
Abstract Magnetic hysteresis and transverse ac permeability measurements in Bi2Sr2CaCu2O8+delta allow a comparative analysis of the critical current with the elastic response of vortex structures, in equilibrium with their pinning potential, in the field and temperature region where the second peak is detected. This study provides strong evidence that the second peak has its origin in changes of the elastic equilibrium properties of the vortex structures.
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 0031-9007 ISBN Medium
Area Expedition Conference
Notes ISI:000170212200049 Approved no
Call Number BT @ hernan @ Serial 215
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Author (down) Correa, V.F.; Herbsommer, J.A.; Kaul, E.E.; de la Cruz, F.; Nieva, G.
Title Order-disorder transition and the zero-dimensional vortex pinning regime in Bi2Sr2CaCu2O8+delta Type Journal Article
Year 2001 Publication PHYSICAL REVIEW B Abbreviated Journal
Volume 63 Issue 9 Pages 092502
Keywords
Abstract We make a comparative study between the ab plane's dc critical current and the ac transverse magnetic permeability μ(perpendicular to) in the Campbell limit for optimally doped and overdoped Bi2Sr2CaCu2O8+delta samples. We focus attention on the low-temperature region [T/T-c(0) < 0.25], where the transition to the zero-dimensional Larkin limit is detected by the critical current as well as by a rapid change of the Labusch parameter with temperature. The order-disorder transition, characterized by the second peak in magnetization, disappears in the presence of this zero-dimensional pinning regime.
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 0163-1829 ISBN Medium
Area Expedition Conference
Notes ISI:000167312000016 Approved no
Call Number BT @ hernan @ Serial 218
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Author (down) Correa, V.F.; Herbsommer, J.A.; Kaul, E.E.; de la Cruz, F.; Nieva, G.
Title Onset of the 0-dimensional vortex pinning behavior in the optimally doped and overdoped Bi2Sr2CaCu2O8+delta system Type Journal Article
Year 2000 Publication PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS Abbreviated Journal
Volume 341 Issue Pages 1285-1286
Keywords
Abstract We report results of transverse AC magnetic permeability in the linear regime and DC magnetization loops for optimally doped and oxygen overdoped samples of Bi2Sr2CaCu2O8+delta The data cover the low temperature (T < 25K) and low held (H-a < 1000 Oe) region of the magnetic (H-a-T) phase diagram. In optimally doped as well as in overdoped samples a crossover to a O-dimensional pinning regime (Larkin length, L-C(C), shorter than the inter-plane CuO2 distance) is observed at a characteristic temperature Too for all investigated fields. The order-disorder transition, identified by the second peak in magnetization and a non monotonous field dependence of the AC penetration depth, is quenched below T-0D.
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 ISI:000165855700242 Approved no
Call Number BT @ hernan @ Serial 221
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Author (down) Civale, L.; Safar, H.; de la Cruz, F.
Title Percolation and glass behavior in ceramic superconductors: oxygen effects Type Journal Article
Year 1989 Publication Modern Physics Letters B Abbreviated Journal Mod. Phys. Lett. B
Volume 3 Issue 2 Pages 173-181
Keywords
Abstract It is shown that small variations of oxygen content in La1.8Sr0.2CuO4−δ can be used to control the reversible and irreversible magnetization temperature dependence of the superconducting state. A grain bond model is appropriate to describe the superconducting response of the ceramics. The study of the temperature dependence of the magnetization and the resistive transition temperature, in a slightly deoxygenated sample, show that the reversible superconducting state is strongly correlated to superconducting percolation. Deoxygenation has been shown to be an excellent technique to study the time evolution of metastable states induced by currents in the bonds and or in the grains. It is shown that superconducting grains are not correlated to ceramic grains.
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 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ pedrazp @ Serial 802
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Author (down) Civale, L.; de la Cruz, F.; Luzuriaga, J.
Title Critical temperature and density of states in amorphous Zr70Cu30 Type Journal Article
Year 1983 Publication Solid State Communications Abbreviated Journal Solid State Commun.
Volume 48 Issue 4 Pages 389-391
Keywords ZIRCONIUM COPPER ALLOYS
Abstract By means of thermal heat treatment of amorphous Zr70Cu30 it is shown that the induced decrease in critical temperature is followed by a reduction in the electronic density of states of the same magnitude as that obtained by changing the Cu concentration. This result indicates that the density of states is the fundamental microscopic parameter determining the superconducting behavior.
Address Centro Atomico Bariloche
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 00381098 (ISSN) ISBN Medium
Area Expedition Conference
Notes Cited By (since 1996): 1; Export Date: 28 April 2009; Source: Scopus; CODEN: SSCOA; Language of Original Document: English; Correspondence Address: Civale, L.; Centro At Approved no
Call Number BT @ luzuriag @ Serial 503
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Author (down) Civale, L.; de la Cruz, F.
Title Anomalous behavior of superconducting samples with a fixed number of vortices Type Journal Article
Year 1987 Publication Physical Review B Abbreviated Journal Phys. Rev. B
Volume 36 Issue 7 Pages 3560-3564
Keywords
Abstract We report an anomalous reversible temperature dependence of the magnetization of amorphous type-II superconductors. The experimental results were obtained studying the vortex pinning in samples with very low vortex concentration. The anomaly is shown to be a consequence of the lack of flux quantization in finite samples.
Address
Corporate Author Thesis
Publisher American Physical Society Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ pedrazp @ 10.1103/PhysRevB.36.3560 Serial 566
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Author (down) Bridoux, G.; Pedrazzini, P.; de la Cruz, F.; Nieva, G.
Title Angular field dependence of the Nernst effect in Bi2Sr2CaCu2O8+delta Type Journal Article
Year 2007 Publication PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS Abbreviated Journal
Volume 460 Issue Pages 841-842
Keywords
Abstract The anomalous Nernst effect in hole-doped cuprates has been interpreted in terms of the existence of a superconducting order parameter well above the transition temperature, T-c(H). In order to improve the understanding of this problem, we have measured the angular field dependence of the Nernst signal in Bi2Sr2CaCu2O8+delta single crystals. The experiment was done tilting the magnetic field with respect to the direction of the temperature gradient, above and below T,(H), with applied fields up to 16 T. We have found that all the curves are scaled on one curve against the reduced field Hcos theta at a fixed temperature. (c) 2007 Elsevier B.V. All rights reserved.
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 ISI:000249870600060 Approved no
Call Number BT @ hernan @ Serial 198
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