High-field properties and scaling in CVD-prepared Nb/sub 3/Ge

Journal Article · Thu Feb 01 04:00:00 EST 1979 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.326021· OSTI ID:6517849

Thompson, J D; Maley, M P; Newkirk, L R; Bartlett, R J

The upper critical field H/sub c/2 and the field-dependent critical current density J/sub c/(H) have been determined for high-T/sub c/ Nb/sub 3/Ge prepared by the chemical vapor deposition (CVD) process. Measurements were performed on short samples taken from long lengths (approx.10 m) of Nb/sub 3/Ge deposited under various conditions onto metallic substrates. Using the theory of Hohenberg and Werthamer for dirty type-II superconductors, values of H/sub c/2(0) were extrapolated from resistive measurements of H/sub c/2 near T/sub c/. Values of H/sub c/2(0) ranged from 32.2 to 33.1 T, the highest upper critical field reported for bulk Nb/sub 3/Ge. From measurements of J/sub c/(H), pinning force densities F/sub p/ were calculated and compared to the Kramer model of flux pinning which predicts certain scaling laws for F/sub p/. We have tested for these scaling laws and have found qualitative agreement with the model of Kramer. This represents the first demonstration of such scaling in bulk high-T/sub c/ Nb/sub 3/Ge. In addition, values of the flux line lattice shearing parameter K/sub s/ have been extracted from our data and are found to be in quantitative agreement with Kramer's predictions.

• Research Organization: Los Alamos Scientific Laboratory, Los Alamos, New Mexico 87545
• OSTI ID: 6517849
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 50:2; ISSN JAPIA
• 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
CHEMICAL COATING
CHEMICAL VAPOR DEPOSITION
CRITICAL CURRENT
CRITICAL FIELD
CURRENTS
DEPOSITION
ELECTRIC CONDUCTIVITY
ELECTRIC CURRENTS
ELECTRICAL PROPERTIES
GERMANIUM ALLOYS
INTERMETALLIC COMPOUNDS
MAGNETIC FIELDS
MAGNETIC FLUX
NIOBIUM ALLOYS
NIOBIUM BASE ALLOYS
PHYSICAL PROPERTIES
SCALING LAWS
SUPERCONDUCTIVITY
SUPERCONDUCTORS
SURFACE COATING
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE
TYPE-II SUPERCONDUCTORS