Accession Number : AD0778498

Title :   Metallurgical and Physical Properties of High-Temperature, High-Critical-Field Superconducting Materials.

Descriptive Note : Final rept. 1 Mar 72-31 Dec 73,

Corporate Author : RCA LABS PRINCETON N J

Personal Author(s) : Webb,George W.

Report Date : FEB 1974

Pagination or Media Count : 18

Abstract : The compositional dependence of T(c) was measured in a system of niobium-based pseudo-binary beta-tungsten systems. In those cases where stoichiometry with respect to niobium could be maintained, T(c) was found to be a monotonic function of composition, suggesting a general rule. However, the critical magnetic field strengths under the same conditions did not scale with T(c) and did in fact sometimes exhibit maxima, proving extrinsic behavior in these materials. A general annealing effect was discovered. The lower-temperature annealing time to reach a given T(c) in quenched specimens could be greatly accelerated by interposing a very short time anneal at somewhat higher temperatures. The high-energy neutron bombardment at room temperature of Nb3Ga, Nb3Al, and Nb3Sn was found to cause 15 K depressions of T(c) which are reversible with short anneals at 750C. (Author)

Descriptors :   *Superconductors, *Intermetallic compounds, Superconductivity, Transition temperature, Niobium alloys, Gallium alloys, Aluminum alloys, Tin alloys, Annealing, High temperature, Magnetic fields

Subject Categories : Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE