Strongly enhanced pinning force density in YBCO-BaTiO3 nanocomposite superconductor

YBa2Cu3O7-delta-BaTiO3 (4 wt.%) (YBCO-BTO (4%)) composite bulk polycrystalline sample has been synthesized by solid state reaction method. The structure of composite sample has been investigated by X-ray diffraction and magnetization measurements were carried out using MPMS SQUID VSM. The superconducting transition temperature of the YBCO-BTO (4%) sample was similar to that of pure YBCO. The critical current density (J(c)) for YBCO-BTO (4%) sample increases significantly as compared to pure YBCO sample. The enhancement of the critical current density in the YBCO-BTO (4%) sample has been attributed to the presence of BaTiO3 nanoparticles acting as artificial pinning centres. The introduction of BaTiO3 particles in YBCO increases pinning force density from 0.71 GN/m(2) to 1.41 GN/m(2) at 4 K and 0.33 MN/m(2) to 0.97 MN/m(2) at 77 K. (C) 2009 Published by Elsevier B.V.