Final rept. 1 Jan 78-31 Dec 82,
WESTINGHOUSE RESEARCH AND DEVELOPMENT CENTER PITTSBURGH PA
Pagination or Media Count:
Both A15 and B1 structure superconductors with nearly optimum critical temperatures were prepared with a range of grain sizes down to the coherence length. In B1 compounds high critical current densities at high fields were obtained due to very large critical fields arising from a small column-void microstructure. Critical current data at low fields demonstrated that grain boundaries are not, invariably, efficient pinning sites. Extremely enhanced current densities were measured only in superconductors B1 whose cross-sectional areas were made similar in size to a single vortex. No increase in critical temperature, which could be attributed to reduced grain sizes, was found. Reversible strain properties of B1 compounds were shown to be superior to those of the A15s.
- Lasers and Masers
- Fabrication Metallurgy
- Electricity and Magnetism