Thermally activated flux creep in the Gd(Ba_2 <i>x</i>Pr_<i>x</i>)Cu₃O₇system

Abstract

The magnetoresistance of single-phase polycrystalline Gd(Ba2−xPrx)Cu3O7+δ samples has been studied within the thermally activated flux creep model. The decrease of pinning energy with applied magnetic field can be scaled to two power-law relations for magnetic fields, smaller and also larger than about 1 kOe. The derived Hc2(T), Hc2(0), and superconducting coherence length ξ show that the Pr doping, similar to weak links, decreases the vortex flux pinning energy. It is also concluded that the substitution of Pr at the Ba site has a more destructive effect on the flux dynamics than Pr at the rare-earth site.