Answers are grounded in this paper and cite their sources.
We report a study of critical current density J/sub c/ as a function of temperature T, magnetic field H, and film thickness d in a series of high quality YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// (YBCO) films. A crossover in the thickness dependence of J/sub c/(H) curves was observed for T>50 K, where thinner film carries significantly lower J/sub c/(H) than thicker film at high fields, while the opposite was observed at low fields. This J/sub c/(H) crossover behavior seems to be a general feature for a superconducting system with a spectrum of pinning density, whose trend opposes to the effective volume faction for J/sub c/. This generalization is supported by examining J/sub c/(H) crossover behaviors observed earlier in the Bi/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O/sub 10+/spl delta//(Bi2223)/Ag tapes irradiated with 5.8 GeV Pb ions, where enhanced J/sub c/(H) at high fields is attributed to the density increase in the columnar flux pinning centers.
No takes yet. Share an insight, caveat, or question.
Li et al. (2005) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: