Department of Physics and Astronomy: Publications and Other Research
Date of this Version
December 1987
Abstract
Measurements of the transport critical-current density (Jc), magnetization Jc, and magnetoresistance in a number of bulk sintered samples of Y1Ba2Cu3O χ from several different laboratories indicate that the transport Jc is limited by weak-link regions between high Jc regions. The weak-link Jc has a Josephson character, decreasing by two orders of magnitude as the magnetic field is increased from 0.1 to 10 mT at 77 K. An examination of the grain-boundary region in Y1Ba2Cu3O χ shows no observable impurities or second phases to the scale of the [001] lattice planes (~12 Å). The effect of intrinsic conduction anisotropy is discussed. A current-transfer model is proposed in which weak conduction along the c axis plays a role in limiting Jc at grain boundaries. Orienting the grains in the powder state during processing may result in enhanced transport Jc in bulk conductors.
Comments
Published by American Institute of Physics. J. Appl. Phys.62, 4821 (1987). © 1987 American Institute of Physics. Permission to use. Journal home page = http://jap.aip.org/jap/.