A method to improve grain boundary current-carrying capability in melt-textured YBa2Cu3O7- delta
- 1 July 1994
- journal article
- Published by IOP Publishing in Superconductor Science and Technology
- Vol. 7 (7), 455-461
- https://doi.org/10.1088/0953-2048/7/7/002
Abstract
A major impediment for many applications of bulk high-Tc superconductors is the extremely low current-carrying capability due to grain boundary weak links. A method has been developed to eliminate secondary phases and reduce microcracks at the grain boundaries in YBCO superconductor by removing a fraction of the liquid phase formed during melt texturing. Samples fabricated using this method consist of large domains containing several grains of oriented platelets with grain boundaries free of secondary phases and microcracks. The processing conditions have been tailored to obtain domains extending over a length of 15 to 20 mm, a width of 8 to 10 mm and a thickness of up to 5 mm. The grain boundary misorientation is characterized by optical microscopy as well as X-ray pole figure analysis. These grain boundaries, though having large misorientation angles up to 27.80 degrees , are found to carry high currents at 77 K, both in self-field and in an applied magnetic field of 1.5 T. These results give promise of the manufacture of polycrystalline YBCO superconductors with high current-carrying capability.Keywords
This publication has 12 references indexed in Scilit:
- Transport properties across high-angle bicrystals of melt-textured YBa/sub 2/Cu/sub 3/O/sub 6+x/IEEE Transactions on Applied Superconductivity, 1993
- A method to control grain-boundary properties in melt-textured YBa2Cu3O7−x superconductorsPhysica C: Superconductivity and its Applications, 1992
- A comparative study of grain boundary structure and critical current density in 123-YBaCuO, 2212-BiSrCaCuO and 2223-TlBaCaCuO high temperature superconductorsMaterials Science and Engineering B, 1991
- Weak-link-free behaviour of high-angle YBa2Cu3O7–δ grain boundaries in high magnetic fieldsNature, 1990
- Quaternary phase relations near YBa2Cu3O6+x at 850°C in reduced oxygen pressuresPhysica C: Superconductivity and its Applications, 1990
- Superconducting transport properties of grain boundaries in bicrystalsPhysical Review B, 1990
- Critical current density and atomic structure of grain boundaries in high-TcsuperconductorsPhilosophical Magazine Part B, 1990
- High current density in bulk YBa2Cu3Ox superconductorApplied Physics Letters, 1989
- Orientation Dependence of Grain-Boundary Critical Currents inBicrystalsPhysical Review Letters, 1988
- Melt-textured growth of polycrystalline with high transport at 77 KPhysical Review B, 1988