Spread of critical currents in thin-film YBa2Cu3O7−x bicrystal junctions and faceting of grain boundary

Abstract

grain-boundary topography has been studied by Atomic Force Microscopy. From results of these measurements we suppose that the maximum values of critical current density might be assigned to the symmetrical facets of grain boundary.

Spreads in Critical Current and Normal Conductance of High-$T_{\rm c}$ dc SQUID

“…The better distribution models are the log-normal distribution [9] and the gamma distribution [12]. Both distribution functions fit the histogram reported in literature [8], [9], [12].…”

“…the series-and parallel-SQUID arrays [4], [5], the superconducting quantum interference grating [6], and the superconducting quantum interference filter (SQIF), [7], are limited by the spread in critical current . Even with the optimized fabrication processes, the significant variation in remains [8], [9]. The origin of the large spread seems intrinsic to the highsuperconductors, of which the coherence length is extremely short, and the high-density defects always exist along the grain boundaries [10], [11].…”

Spread of critical currents in thin-film YBa/sub 2/Cu/sub 3/O/sub 7-x/ bicrystal junctions and faceting of grain boundary

“…We have used the sample layout, which is similar to the previously described one [3]. To study a statistical distribution of the critical current of GBJJ we have prepared a special set of samples.…”

“…In this work we use a laser probing for the same task. For LSM measurements we have used an experimental set-up similar to the one described previously [3].…”

Normal-state properties of high-angle grain boundaries in(Y,Ca)Ba2Cu3OMennema1, Ransley2, Burnell3 et al. 2005Phys. Rev. B7080View full textAdd to dashboardCite

“…Such variations are not surprising, since the boundaries themselves are extremely inhomogeneous and previous work on bicrystalline junction arrays has shown that macroscopic transport properties can vary greatly along the length of a single grain boundary. [20][21][22][23] There is also a small device to device error that is due to resistance imbalance of the bridge. These errors have been minimised by taking the mean of all the 5 devices on a single boundary.…”