Addition of Nanoparticle Dispersions to Enhance Flux Pinning of the YBa2Cu3O7-x Superconductor
Journal article, 19 Aug 2003-19 Aug 2004
AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH PROPULSION DIRECTORATE
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After the discovery of type-II HTS, focus is to develop these materials for power applications. One of the problems has been that magnetic flux is not completely expelled but rather contained within magnetic fluxons, whose motion stops larger supercurrents. Its known that the critical current of these materials can be enhanced by incorporating a high density of extended defects to act as pinning centres for the fluxons. YBa2Cu3O7 YBCO or 123 is the most promising material for such applications at higher temperatures. Pinning is optimized when the size of the defects approaches the superconducting coherence length 2-4nm for YBCO at temperatures 8804 77 K and when the areal number density of defects is of the order of H2 x 1011 cm-2, where H is the applied magnetic field in tesla. Such a high density has been hard to get by material-processing methods that keep a nanosize defect, except through irradiation. Here we report a method for achieving a dispersion of 8-nm-sized nanoparticles in YBCO with a high number density, which increases critical current at 77 K by a factor of two to three for high magnetic fields.
- Inorganic Chemistry
- Physical Chemistry