References of "Godelaine, P. A"
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See detailSTUDY OF THE CRYSTALLIZATION PROCESS IN BI2-XPBXSR2CA2CU3O10-Y GLASS SYSTEMS - OPTICAL POLARIZED-LIGHT MICROSCOPY, ELECTRICAL AND MAGNETIC-PROPERTIES
Cloots, Rudi ULg; Romain, Anne-Claude ULg; Rulmont, André ULg et al

in Superconductor Science & Technology (1993), 6(12), 850-857

Synthesis of Bi2-xPbxSr2Ca2Cu3O10-y (x = 0 and x = 0.3) has been performed using the glass recrystallization route technique. After splat quenching, the samples were annealed at 820, 850 or 870-degrees-C ... [more ▼]

Synthesis of Bi2-xPbxSr2Ca2Cu3O10-y (x = 0 and x = 0.3) has been performed using the glass recrystallization route technique. After splat quenching, the samples were annealed at 820, 850 or 870-degrees-C for 96 or 144 h (with one intermediary grinding). High-resolution polarization micrographs and electrical (and magnetic susceptibility) measurements have been taken. Various growth mechanisms can thus be checked, and the physical properties are studied in relation to the microstructure. It is found that the 2223 phase does not crystallize directly from the amorphous one but results from a dissolution-reprecipitation process. The stability of the 2212 phase is emphasized. The 2201 phase precipitates at high temperature and rapidly reacts with the melt to form the 2223 phase. The kinetics of the lead-substituted sample seems to be controlled by the Ca2PbO4 phase. which acts as a flux. [less ▲]

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See detailSuperconductivity fluctuations in Bi(Pb) based granular ceramics superconductors: evidence for fractal behavior
Ausloos, Marcel ULg; Laurent, Christian; Patapis, S. K. et al

in Zeitschrift für Physik. B, Condensed Matter (1991), 83(3), 355-359

We report precise measurements of the electrical resistivity in three different Bi(Pb) based granular ceramics superconductors. We show that a single critical exponent (5/6) describes the ... [more ▼]

We report precise measurements of the electrical resistivity in three different Bi(Pb) based granular ceramics superconductors. We show that a single critical exponent (5/6) describes the superconductivity fluctuations. Such a critical exponent indicates a fractal behavior of the superconducting path. Our results thus indicate a strict two dimensional fluctuation percolation set (below the superconductivity onset temperature 195 K down to T(c)), and provide some proof for Tarascon et al. "shell conductivity path" hypothesis. We estimate the shell thickness to be of the order of 10 angstrom. [less ▲]

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