Pinning enhancement of YBa/sub 2/Cu/sub 3/O/sub 7-d/ thin films with Y/sub 2/BaCuO/sub 5/ nanoparticulates

Abstract

A comparison study is given of a typical superconducting YBa/sub 2/Cu/sub 3/O/sub 7-d/ (Y123) film and a Y123 film containing a nonsuperconducting Y/sub 2/BaCuO/sub 5/ (Y211) phase nanoparticulate dispersion. The inclusion of the second phase nanoparticulates was for the express purpose of increasing superconducting film's magnetic pinning strength with the resultant improved in-field critical current density. LaAlO/sub 3/ substrates were used and the Y123 and Y211 nanoparticulates were grown by pulsed laser deposition (PLD). The Y211 nanoparticulate dispersion in the Y123 resulted from multiple consecutive depositions by PLD of the respective targets. The Y123 phase maintained excellent epitaxy with high in-plane orientation with and without the Y211 inclusions. With the Y211 additions, the critical current densities of the films increased significantly in applied magnetic fields as compared to the high quality Y123 film with no Y211 additions.