Thermally activated flux motion in artificially grown YBa2Cu3O7/PrBa2Cu3O7 superlattices

Abstract

We have studied the thermally activated flux-flow resistance in ${\mathrm{YBa}}_2$ ${\mathrm{Cu}}_3$ ${\mathrm{O}}_7$/${\mathrm{PrBa}}_2$ ${\mathrm{Cu}}_3$ ${\mathrm{O}}_7$ (YBCO/BrBCO) artificial superlattices in magnetic fields perpendicular to the a-b plane. We find for multilayers with thick enough (>24 Å) insulating PrBCO layers and for YBCO thicknesses smaller than 300 Å that the activation energy has a logarithmic magnetic field dependence and that is is proportional to the YBCO thickness in the multilayer.