Processing of Mixed Oxide Superconductors
Abstract
A reasonably complete understanding of the macroscopic consequences of the granular nature of high Tc materials has been obtained. Levitation, damping, and screening are all consistent with the picture of large intergrain currents and small intergrain currents. Magnetic separation works well for YBCO in liquid nitrogen. The technique can certainly be extended to other materials but for practical purposes problems may occur due to the large penetration depth and small size of new materials when first prepared. The causes of, and solutions to, the problem of weak links at grain boundaries remain obscure. The work has shown that there is a close link between the intergrain and intragrain currents and that the short coherence length of oxide superconductors is not the main problem. The closest correlation seems to be with the depairing current so that we should look for materials or dopants which decrease the London penetration depth or increase the thermodynamic critical field. Future work should concentrate on this area and in particular follow up the clues offered by recent excellent results on Bi based superconductors at low temperatures. Keywords: Superconductors.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1989
- Accession Number
- ADA228002
Entities
People
- A. M. Campbell
- M. F. Ashby
Organizations
- University of Cambridge