Flux creep and vortex potential well structure in high-temperature superconductors

The resistive transition and the V-I characteristics in the presence of a magnetic field in epitaxial films of YBa2Cu3O7, Bi2Sr2CaCu2O8, YBa2Cu2.985Ag0.015O7, and GdBa2Cu3O7/ YBa2Cu3O7 multilayers have been investigated. The common qualitative features of all the systems are the current dependent thermally activated resistivity and the power law V-I characteristics at elevated current densities. An extended flux creep model, which incorporates the shape of the vortex potential well, is shown to account for these results. © 1990.