Magnetic field effects on electrical resistivity of (Gd_(1-x)Pr_x)Ba_2Cu_3O_(7-δ) and Gd(Ba_(2-x)Pr_x)Cu_3O_(7+δ)

摘要

The magnetoresistance measurements of single phase polycrystalline Gd(Ba_(2-x)Pr_x)Cu_3O_(7+δ) and (Gd_(1-x)Pr_x)Ba_2Cu_3O_(7-δ) samples have been compared and analyzed by the Ambegaokar and Halperin phase slip model. The derived power law dependences of pinning energy to applied magnetic field and temperature have been studied for different amounts of Pr doping. The power factors depend on the Pr doping. Moreover, in both systems, the magnetic field dependence of the pinning energy power factor increases for small amounts of Pr doping, while for larger amount of Pr doping, it decreases. The critical current power law dependence to magnetic field decreases with increasing Pr doping. Pr substitution at Ba or rare earth site, decreases the pinning energy and the critical current density, playing the role of weak links.