Title :
Thermodynamically controlled melt processing to improve bulk materials
Author :
Krabbes, G. ; Schatzle, P. ; Bieger, W. ; Fuchs, G. ; Wiesner, U. ; Stover, G.
Author_Institution :
Inst. fur Festkorper- und Werkstofforschung e.V., Dresden, Germany
fDate :
6/1/1997 12:00:00 AM
Abstract :
High quality melt textured YBCO samples have been prepared on a modified MTG route. A trapped magnetic field of 8.5 T at 51.5 K was measured in the gap of 1 mm in a mini-magnet from two YBCO cylinders (d=26 mm, h=12 mm). At 77 K, each single domain cylinder traps more than 600 mT and the levitation pressure of 15 N/cm/sup 2/ in a distance of 0.5 mm was achieved by a 0.4 T SmCo magnet. The thermodynamic background of the preparation method is outlined. A thermodynamic approach to control growth and stoichiometry y in the alternative material Nd/sub 1+y/Ba/sub 2-y/Cu/sub 3/O/sub x/ is discussed. Critical currents of 46 kA/cm/sup 2/ (77 K) have been achieved by a modified recipe.
Keywords :
barium compounds; critical current density (superconductivity); crystal growth from melt; flux-line lattice; high-temperature superconductors; magnetic levitation; penetration depth (superconductivity); stoichiometry; superconducting magnets; yttrium compounds; 1 mm; 51.5 K; YBCO cylinders; YBa/sub 2/Cu/sub 3/O/sub 7/; bulk materials; critical currents; high temperature superconductor; levitation pressure; mini-magnet; single domain cylinder; thermodynamic background; thermodynamically controlled melt processing; trapped magnetic field; Critical current; Magnetic domains; Magnetic field measurement; Magnetic levitation; Magnetic materials; Melt processing; Neodymium; Process control; Thermodynamics; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
