Superconducting and microstructural properties of [001] tilt YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// thick film grain boundaries on SrTiO/sub 3/ bicrystal substrates

We present a study of superconducting and microstructural properties of [001] tilt YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// (YBCO) thick film grain boundaries (GB) on SrTiO/sub 3/ bicrystal substrates prepared using a BaF/sub 2/ ex-situ post deposition reaction process. For a 15/spl deg/ tilt boundary, multiple microbridges were patterned across the grain boundary at various locations. A large variation of local critical current density J/sub c/ was observed. Through local microstructural characterization of these GB bridges using transmission electron microscopy (TEM), a direct correlation of local GB J/sub c/ with structure is identified.