Effect of ZrO2 and ZnO nanoparticles inclusions on superconductive properties of the melt-processed GdBa2Cu3O7-δ bulk superconductor

Single domain Gd123 bulk superconductors have been fabricated successfully with doping both ZrO2 and ZnO nanoparticles by a hot seeded melt growth in air. Superconductive properties were studied on the specimens selected from different positions of the domain separately, along the a-b plane and c-axis. The nanosized defects induced by the nanoparticles can be effective pinning center to enhance the J(c) of the bulk. Atomic substitution of Cu site with Zn ion enables us to enhance the J(c) but the substitution suppresses the T-c of the bulk. By the analysis of the pinning force, for the specimens cut along the a-b plane, the delta I pinning is enhanced by the addition of nanoparticles. While for the specimens cut along the c-axis, the delta T-c pinning is remarkably enhanced. (C) 2008 Elsevier B.V. All rights reserved.