Title :
Enhanced superconducting properties in Bi/sub 2/Sr/sub 2/Ca/sub 1/Cu/sub 2/O/sub y/ by thermal and mechanical processing
Author :
Miller, D.J. ; Holesinger, T.G. ; Hettinger, J.D. ; Goretta, K.C. ; Gray, K.E.
Author_Institution :
Argonne Nat. Lab., IL, USA
fDate :
3/1/1993 12:00:00 AM
Abstract :
The effect of processing on transition temperature, grain boundary coupling, and flux pinning has been examined for Bi/sub 2/Sr/sub 2/Ca/sub 1/Cu/sub 2/O/sub y/. Enhancement of critical temperature based on composition can be achieved by control of crystallization and subsequent annealing processes while thermomechanical processing may be used to modify weak link and flux pinning behavior. The microstructural basis for these changes is related to the composition of the superconducting phase and the presence of defects associated with deformation processing. The implications of these results for conductor development are related to the selection of alloy composition for optimum transition temperature and controlled thermomechanical processing which yields a uniform defect structure.<>
Keywords :
annealing; bismuth compounds; crystal microstructure; crystallisation; dislocation structure; flux pinning; grain boundaries; high-temperature superconductors; superconducting transition temperature; thermomechanical treatment; Bi/sub 2/Sr/sub 2/Ca/sub 1/Cu/sub 2/O/sub y/; HTSC; annealing processes; composition; critical temperature; crystallization; flux pinning; grain boundary coupling; mechanical processing; microstructural basis; thermomechanical processing; transition temperature; uniform defect structure; Annealing; Bismuth; Conductors; Crystallization; Flux pinning; Grain boundaries; Strontium; Superconducting transition temperature; Temperature control; Thermomechanical processes;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
