Accession Number : ADA019558

Title :   Synthesis and Metallurgical Properties of Intermetallic Compounds.

Descriptive Note : Final rept.,

Corporate Author : CALIFORNIA UNIV SAN DIEGO LA JOLLA INST FOR PURE AND APPLIED PHYSICAL SCIENCES

Personal Author(s) : Webb,George W. ; Arrhenius,Gustaf

Report Date : NOV 1975

Pagination or Media Count : 7

Abstract : The connections between synthesis conditions, metallurgical properties and physical properties were investigated in the highest T sub C niobium based A-15 superconducting compounds. Thick chemically vapor deposited Nb3Ge deposits with T sub C up to 23.0 K were prepared using a new original vapor deposition apparatus. New results from closed tube iodide transport show that the range of compositions which 'Nb3Ga' exists extends from 75 at. % Nb to 90 at. % Nb, that is from Nb3Ga to Nb9Ga, a much broader range than was known. Iodide transport of Nb3Sn was successful in producing single crystals having resistance ratios as high as 20, more than a factor of two higher than previously reported. The low temperature resistivities of Nb3Ge, Nb3Al and Nb3Sn were found to follow a T2 law from T sub C to 40 K. Measurements on the effect of neutron damage induced disorder in Nb3Sn, Nb3Al and Nb3Ga were extended and in Nb3Al a large lattice parameter expansion with damage was found which could be related to site exchange disorder. (Author)

Descriptors :   *Superconductors, *Superconductivity, *Intermetallic compounds, *Niobium compounds, Germanium compounds, Gallium compounds, Aluminum compounds, Tin compounds, Single crystals, Metallurgy, Physical properties, Synthesis(Chemistry), Vapor deposition, Damage, Radiation effects, Neutrons, Niobium alloys, High temperature, Low temperature, Crystal growth

Subject Categories : Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE