High magnetic field properties of CVD-prepared Nb/sub 3/Ge and Nb/sub 3/(Ge,X/sup +/)

Journal Article · Mon Jan 01 04:00:00 EST 1979 · IEEE Trans. Magn.; (United States)

DOI:https://doi.org/10.1109/TMAG.1979.1060253· OSTI ID:5255447

Thompson, J D; Maley, M P; Newkirk, L R; Carlson, R V

Measurements of the field dependent critical current density, J/sub c/(H), and the upper critical field, H/sub c2/, have been performed on a number of Nb/sub 3/Ge samples prepared by the chemical vapor deposition (CVD) process. These samples, obtained from up to 20 m lengths of Nb/sub 3/Ge tape, were deposited on various substrates at temperatures between 835 and 950/sup 0/C. Flux pinning, provided by the introduction of controlled amounts of second phase precipitate, Nb/sub 5/Ge/sub 3/, produced good high field properties with 4.2 K critical current densities on the order of 8.3 x 10/sup 4/ A/cm/sup 2/ at 18 T. Measurements of J/sub c/(H) performed on these samples in both liquid helium and hydrogen in fields up to 18.5T have been analyzed in terms of Kramer's model of flux pinning. Qualitative agreement has been found with the scaling laws predicted by this theory. The effect of ternary additions of Si and Ga on both H/sub c2/ and J/sub c/(H) have been investigated as well. Contrary to expectation, the addition of ternaries into the A-15 lattice results in somewhat depressed critical characteristics. The effect of deposition parameters on the high field properties of both Nb/sub 3/Ge and Nb/sub 3/(Ge,X) will be discussed.

• Research Organization: Los Alamos Scientific Lab., NM
• OSTI ID: 5255447
• Journal Information: IEEE Trans. Magn.; (United States), Journal Name: IEEE Trans. Magn.; (United States) Vol. MAG-15:1; ISSN IEMGA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104 -- Metals & Alloys-- Physical Properties
656102* -- Solid State Physics-- Superconductivity-- Acoustic
Electronic
Magnetic
Optical
& Thermal Phenomena-- (-1987)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALLOYS
BETA-W LATTICES
CRITICAL FIELD
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTAL-PHASE TRANSFORMATIONS
GERMANIUM ALLOYS
INTERMETALLIC COMPOUNDS
MAGNETIC FIELDS
MAGNETIC FLUX
NIOBIUM ALLOYS
NIOBIUM BASE ALLOYS
PHASE TRANSFORMATIONS