Effect of Barium Titanate and Titania Additions on the Microstructure and Critical Current Density of Yttrium Barium Cuprate Ceramics

摘要

Fine-particle BaTiO_3 and TiO_2 additions are shown to have a significant effect on the structure, microstructure, and superconducting properties of Yba_2-Cu_3O_7-δ ceramics prepared via partial melting. The ranges of solid solutions are determined. The additions are found to enhance the critical current density by a factor of 1.5-2.5. X-ray microanalysis of individual grains in the doped ceramics indicates an increased con- centration of small inclusions, presumably Y_2BaCuO_5, embedded in superconducting grains and acting as pin- ning sites.