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Arce, R., L. Civale, J. Luzuriaga, J. Guimpel, and F. de la Cruz. "Surface normal regions in superconducting Zr70Cu30 induced by thermal relaxation." Solid State Communications 48, no. 12 (1983): 1027–1030.
Abstract: Penetration depth measurements show that thermal heat treatment in amorphous Zr70Cu30 induces a normal region 5000 Å thick at the surface of ultrarapid quenched ribbons. Upper critical field measurements indicate that the new induced phase is a normal one while the rest of the sample remains as a homogeneous superconducting phase.
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Arce, R., F. de la Cruz, and P. Esquinazi. "Superconducting penetration depth in amorphous metals." Solid State Communications 38, no. 12 (1981): 1253–1255.
Abstract: We show that temperature dependent penetration depth measurements can be used to characterize the superconductive behaviour of amorphous metals.
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Arce, R., F. de la Cruz, and H. J. Fink. "Model relating superconductive penetration depth and metallurgical phase separation in amorphous La70Cu30." Solid State Communications 42, no. 8 (1982): 575–577.
Abstract: A model is proposed to account for the large increase in the measured penetration depth of superconducting, amorphous La70Cu30 when the specimens are annealed sufficiently long near, but below, the crystallization temperature. It is suggested that a metallurgical phase separation occurs with domain dimensions in the submicrometer range. Penetration depth measurements as a function of temperature in a weak magnetic field are a useful tool to detect changes in phase separation in high-K materials.
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Arce, R., F. de la Cruz, and J. Guimpel. "Superconducting behavior of amorphous Zr70Cu30." Solid State Communications 47, no. 11 (1983): 885–887.
Abstract: Measurement of the Meissner penetration depth, λ(T) were made in amorphous Zr70Cu30 samples. The results indicate that this amorphous alloy behaves as a BCS superconductor with 2Δ(0)+45 degree rulekTc = 3.8, where Δ(0) is the superconducting energy gap at T=0 and Tc the critical temperature. It is also concluded that the low energy excitation, TLS, characteristics of amorphous material does not contribute to Tc.
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Braun, E., A. Bürger, B. Roden, and J. G. Sereni. "Spin glass-like behaviour of the singlet ground state system: ThTb." Solid State Communications 66, no. 11 (1988): 1141–1144.
Abstract: We have studied the temperature and field dependence of the magnetic susceptibility, X, on the single-ground-state Th1?nTbn system, in the 0.2 < n < 0.6 concentration range. The characteristic maximum of a spin glass transition was found at a temperature Tg, which increases linearly with the impurity concentration. As expected, the maximum of X is reduced by the increment of the applied magnetic field. The spin glass order parameter, as well as its critical exponent were evaluated by using the Sherrington-Kirkpatrick theory.
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Bressan, O. J., A. E. Ridner, C. A. Luengo, and B. Alascio. "On the evidence for electron-electron scattering in the electrical resistivity of In." Solid State Communications 8, no. 24 (1970): 2129–2133.
Abstract: Experimental measurements of the electrical magnetoresistivity of high purity Indium at low temperatures have been performed and clearly indicate that:
1. (a) A generalized Kohler's rule can be used to describe all experiments.
2. (b) A reliable method is therefore obtained for extrapolating the zero magnetic field resistivity to temperatures below the superconducting transition temperature.
3. (c) Clear-cut and reliable data show that no T2 dependence of the resistance is found; therefore no evidence of electron-electron interaction appears, contrary to information previously reported in the literature.
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Castello, D., M. Jaime, and M. Núñez Regueiro. "Thermal conductivity of high temperature superconductor TlBaCaCuO." Solid State Communications 79, no. 11 (1991): 967–970.
Abstract: We have measured the thermal conductivity of ceramic samples of TlBaCaCuO between 2 and 250 K. At high temperatures it follows a constant behaviour down to the superconducting transition temperature where a sudden increase of the thermal conductivity occurs, attributed to reduced phonon scattering by condensating electrons. At low temperatures a T2 law is observed, confirming the assumption that it is a common feature in most of the high temperature superconducting oxides. Phonon scattering against tunneling systems analogous to those found in amorphous solids can explain this behaviour.
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Civale, L., F. de la Cruz, and J. Luzuriaga. "Critical temperature and density of states in amorphous Zr70Cu30." Solid State Communications 48, no. 4 (1983): 389–391.
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.
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Civale, L., H. Pastoriza, F. de la Cruz, J. Guimpel, G. Nieva, J. M. Heintz, O. Durmeyer, and J. P. Kappler. "Meissner fraction of insulating samples of oxide superconductors." Solid State Communications 72, no. 4 (1989): 341–344.
Abstract: The tendency towards superconducting granularity with sample degradation is a common feature of oxide superconductors. We present magnetic, transport and calorimetric results in LiTi$2Ο4$ which show that the topological tendency to segregate the superconducting state into islands surrounded by thin insulating layers is related to the structure of the material rather than to a mechanism associated to high T$_C$. We emphasize that insulating samples with small Meissner fraction can have a superconducting volume fraction close to unity.
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Daudin, B. "Thermal conductivity of amorphous La70Cu30." Solid State Communications 37, no. 2 (1981): 149–152.
Abstract: We have measured in a temperature range of 0.6 to 6.5 K the thermal conductivity of various samples of amorphous La70Cu30 prepared by ultra rapid quenching. Below the superconducting critical temperature (Tc=3.85K) we found the classical amorphous behaviour and determined the coupling constant n0M2. Above Tc we found that the thermal conductivity was governed by the electron-phonon interaction and we discuss the results obtained.
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