Title :
Critical currents, magnetic relaxation and microstructure in zone-melted YBa2Cu3Ox
Author :
Shi, Dequan ; Chen, Jingguang G. ; Xu, Mengdi ; Chen, W.H. ; Goretta, K.C.
Author_Institution :
Argonne Nat. Lab., IL, USA
fDate :
3/1/1991 12:00:00 AM
Abstract :
Extruded YBa2Cu3Ox wires have been zone-melted to develop highly textured microstructures. The zone-melted wires exhibit large magnetic hysteresis and transport J c values relative to conventional bulk YBa2Cu 3Ox. The transport Jc in the zone-melted wire, in magnetic fields up to 1.5 T, has been greatly improved at 77 K. Transmission-electron-microscope evidence suggests that this enhancement of Jc may be connected with small-angle grain boundaries. The magnetic hysteresis loop at 77 K in the zone-melted wire is largely increased relative to that for a sintered specimen. This increase in the hysteresis loop may possibly be attributed to a high density of dislocations acting as strong pinning centers
Keywords :
barium compounds; critical current density (superconductivity); crystal microstructure; dislocations; flux pinning; grain boundaries; high-temperature superconductors; magnetic hysteresis; magnetic relaxation; texture; yttrium compounds; 77 K; TEM; YBa2Cu3Ox; critical currents; dislocations; extruded wires; high temperature superconductivity; hysteresis loop; magnetic hysteresis; magnetic relaxation; microstructure; pinning centers; small-angle grain boundaries; texture; transport Jc; zone-melted wires; Creep; Critical current density; Grain boundaries; Magnetic hysteresis; Magnetic materials; Microstructure; Powders; Superconducting materials; Transmission electron microscopy; Wires;
Journal_Title :
Magnetics, IEEE Transactions on
