Fluxoid pinning by grain boundaries in bicrystals and polycrystals of niobium

Conference · Fri Jan 01 04:00:00 EST 1982

OSTI ID:5322970

Cai, B C; DasGupta, A; Chou, Y T; Scarbrough, J O; Koch, C C

In niobium bicrystals of various preassigned misorientations, the superconducting critical current, I/sub c/ has been measured as a function of the applied magnetic field, H, and the azimuthal angle, phi, between the grain boundary and H. Frequently, peaks in I/sub c/(phi) with half width ..delta..phi 1/2 approx. 30/sup 0/, as well as high pinning force, f/sub p/ up to 10/sup -4/ Nm/sup -1/ at 0.2 T have been found for H both parallel and perpendicular to the grain boundary plane. Using f/sub p/ and ..delta..phi 1/2, obtained from bicrystals, the critical current density, J/sub c/, has been calculated for polycrystalline samples. The results are in good agreement with experimental measurements both in magnitude and grain in size dependence.

• Research Organization: Oak Ridge National Lab., TN (USA); Lehigh Univ., Bethlehem, PA (USA). Dept. of Metallurgy and Materials Engineering
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5322970
• Report Number(s): CONF-820546-7; ON: DE82017406
• 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
CRITICAL CURRENT
CRYSTAL STRUCTURE
CRYSTALS
CURRENTS
ELECTRIC CONDUCTIVITY
ELECTRIC CURRENTS
ELECTRICAL PROPERTIES
ELEMENTS
GRAIN BOUNDARIES
MAGNETIC FIELDS
MAGNETIC FLUX
METALS
MICROSTRUCTURE
NIOBIUM
PHYSICAL PROPERTIES
SUPERCONDUCTIVITY
SUPERCONDUCTORS
TRANSITION ELEMENTS
TYPE-II SUPERCONDUCTORS