Title :
Directional solidification of bulk (Y,Sm,Nd)/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7-x/
Author :
Boffa, M. ; Di Trolio, A. ; Pace, S. ; Saggese, A. ; Vecchione, A. ; Camarota, B. ; Sparvieri, N.
Author_Institution :
Dipartimento di Fisica, Salerno Univ., Italy
fDate :
6/1/1997 12:00:00 AM
Abstract :
Rare Earth (Nd,Sm) elements, having relatively large ionic radius, have been substituted for Yttrium in Y123 superconducting melt textured bulk samples. In (Nd,Sm)123 a wider solidification range and higher recrystallization rate than Y123 significantly increase the solidification rate, making the whole process much faster. A preliminary comparison among directionally solidified (Y,Sm,Nd)/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7-x/ bulk bars fabricated by the Horizontal Bridgman method has been done. The different microstructural and superconducting features are studied by X-ray, SEM analysis, and ac and dc magnetic measurements. The (Nd,Sm)123 samples, appear comparable to Y123 grown with a pulling rate almost two orders of magnitude lower.
Keywords :
X-ray diffraction; barium compounds; crystal growth from melt; crystal microstructure; directional solidification; high-temperature superconductors; magnetic hysteresis; magnetic susceptibility; neodymium compounds; recrystallisation; samarium compounds; scanning electron microscopy; yttrium compounds; (Y,Sm,Nd)/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7-x/; (YSmNd)Ba/sub 2/Cu/sub 3/O/sub 7/; SEM; X-ray diffraction; directional solidification; horizontal Bridgman method; magnetic measurements; melt textured bulk samples; microstructure; recrystallization rate; superconducting features; Atomic measurements; Bars; Critical current; Furnaces; Granular superconductors; High temperature superconductors; Neodymium; Samarium; Solids; Superconducting integrated circuits;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
