Electromagnetic and Nanostructural Studies of Rare Earth Copper Oxide Grain Boundaries Grain Boundaries in High Temperature Superconductors
Abstract
There is strong Air Force interest in compact, airborne, high-power generators and klystron/gyrotron/magnetron magnets. Both applications need superconducting magnets that can operate off robust cryocoolers at temperatures near liquid nitrogen (77K). The decisive element for all such applications is the conductor from which such magnets can be made. The material of choice is YBa2Cu3O7-x, made in the form of a multilayer tape as a Coated Conductor (CC). Such conductors are multilayers of ~50 micrometers-thick Ni-alloy to support an ~1 micrometer-thick buffer layer (for now generally Y2O3/YSZ/CeO2) ~2-5 micrometers YBa2Cu3Ox layer, all topped by a high-conductivity, normal-metal overlayer for stabilization and protection. The single most important characteristic of any CC is the need for texture in the superconductor so that blockage of current at grain boundaries is minimized. Texture is vital, since even low angle grain boundaries partially obstruct the current, reducing the global Jc and providing significant local sources of dissipation that may induce instabilities during magnet use. Understanding why grain boundaries block current and searching for ways to mitigate the problem forms the central thrust of this work.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2006
- Accession Number
- ADA471690
Entities
People
- Alex Gurevich
- David C. Larbalestier
Organizations
- University of Wisconsin–Madison