Guimpel, J., F. de la Cruz, J. Murduck, and I. K. Schuller. "Penetration depth of a superconducting superlattice." Physical Review B 35, no. 7 (1987): 3655–3656.
Abstract: We have measured the magnetic-flux expulsion of a superconducting superlattice and related it to the Meissner penetration depth. The temperature dependence of the penetration depth is in quantitative agreement with theoretical expectation based on mean-field theory. The zero-temperature penetration depth is found in excellent, quantitative agreement without adjustable parameters with theoretical predictions for dirty superconductors.
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Guimpel, J., and F. de la Cruz. "Electrical resistivity of amorphous Zr70Cu30 and the Kondo like model." Solid State Communications 44, no. 7 (1982): 1045–1046.
Abstract: Electrical resistivity measurements of amorphous Zr70Cu30 as a function of the concentrations of two level systems show that a Kondo like theory cannot explain the observed temperature dependence.
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Guimpel, J., L. Civale, F. de la Cruz, J. M. Murduck, and I. K. Schuller. "Dimensional phase transition in superconductors with short coherence length." Physical Review B 38, no. 4 (1988): 2342–2344.
Abstract: We found a novel dimensional transition in the vortex lattice of a finite-sized superconductor. The low-field dependence (with field applied parallel to the film plane) of the magnetization exhibits two maxima, which signal the transition from one to two dimensions. In one dimension the vortices line up along the film, and with increasing field their arrangement changes into a two-dimensional array due to the competition between vortex-surface and vortex-vortex repulsion. Agreement is found with no adjustable parameter calculations using a priori known surface-barrier and vortex-repulsion effects.
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Grigera, S. A., E. Morre, E. Osquiguil, G. Nieva, and F. de la Cruz. "Two-step liquid-solid vortex transition with the field along the ab planes in YBa2Cu3O7-delta crystals." PHYSICAL REVIEW B 59, no. 17 (1999): 11201–11204.
Abstract: Resistivity measurements for different Lorentz force configurations and the detection of the longitudinal vortex velocity correlation length, with the magnetic field applied parallel to the ab planes, in the mixed state of clean and twinned YBa2Cu3O7-delta single crystals,' support the existence of a vortex-smectic phase when the vortices interact with an attractive periodic potential. The transition from the vortex-liquid to the vortex-solid state is shown to be achieved in two steps, a continuous transition from a liquid to a possible smectic phase and another continuous one from the smectic phase to a solid. [S0163-1829(99)09413-8].
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Grigera, S. A., E. Morré, E. Osquiguil, G. Nieva, and F. De la Cruz. "Nonlocal transport properties and size effects in heavily twinned YBa2Cu3O7-delta single crystals." Solid State Communications 107, no. 7 (1998): 335–339.
Abstract: We demonstrate experimentally that when the vortex correlation length in the liquid state becomes of the order of the sample thickness, size effects dominate the transport properties of the macroscopic vortex structures, implying a nonlocal response in the transformer experiments.
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Grigera, S. A., E. Morre, E. Osquiguil, C. Balseiro, G. Nieva, and F. de la Cruz. "Bose-glass phase in twinned YBa2Cu3O7-delta." PHYSICAL REVIEW LETTERS 81, no. 11 (1998): 2348–2351.
Abstract: Using an extensive scaling analysis of the transport properties in twinned YBa2Cu3O7-delta crystals we have experimentally found the predicted change in the universality class of the Bose-glass to liquid transition when the magnetic field is applied at small angles away from the direction of the correlated defects. The new dynamical critical exponent is s' = 1.1 +/- 0.3.
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Grigera, S. A., T. S. Grigera, E. F. Righi, G. Nieva, and F. de la Cruz. "Flux-cutting in YBa2Cu3O7-delta revisited." PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS 371, no. 3 (2002): 237–242.
Abstract: In this paper we present an analysis of the response of the vortices in YBa2Cu3O7-delta to different configurations of applied driving forces. The use of inhomogeneous current allows us to induce vortex cutting. We determine the maximum current injected in different electrical contact distributions which preserves vortex integrity, and we show that vortex cutting cannot be explained by a single vortex picture. (C) 2001 Elsevier Science B.V. All rights reserved.
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Ferrari, H., S. O. Valenzuela, V. Bekeris, J. Guimpel, and F. de la Cruz. "Short-time magnetization in superconducting thin films." REVISTA MEXICANA DE FISICA 44 (1998): 193–195.
Abstract: We have investigated the magnetization in thin (Y;Gd)Ba2Cu3O7-delta superconducting films in the 100 μs time scale. Magnetic moment was measured with a non-conventional technique that combines the use of a pulsed magnetic field and a synchronized pulsed laser. Both virgin and magnetically cycled samples were examined and results are described within Bean's critical state model.
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Favaron, J., M. E. de la Cruz, P. Esquinazi, and F. de la Cruz. "Phase diagram and superconductive properties of splat-cooled CuxLa1-x." Physical Review B 21, no. 7 (1980): 2804–2808.
Abstract: The phase diagram of nonequilibrium, splat-cooled CuxLa1-x is interpreted by means of superconductive-transition and x-ray measurements. At the eutectic composition the material is shown to be in a highly disordered state. Measurements of dc resistance and ac susceptibility show that there are two different critical fields at the disordered concentration although there is a unique critical temperature.
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Fasano, Y., M. Menghini, F. de la Cruz, and G. Nieva. "Weak interaction and matching conditions for replicas of vortex lattices." PHYSICAL REVIEW B 62, no. 22 (2000): 15183–15189.
Abstract: We present experiments demonstrating the conditions under which weak interaction between replicas of vortex structures break their translational and rotational symmetry. The Fe clumps introduced by Bitter decorations of vortex structures are used to induce an extremely weak interaction fur subsequent vortex structures in low and high temperature superconducting crystals. The matching between the Fe pattern acid the vortex configuration require the structure to be prepared under quite stringent conditions: The field creating the structure has to be the same in magnitude although it can differ in orientation from that used for the preparation of the Fe pattern. The interaction between vortex replicas as represented by the Fe clumps of Bitter decorations makes it possible to differentiate the vortex nucleation and propagation mechanisms in low and high temperature superconductors.
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