Title :
Effect of controlled carbon impurities on Jc in Ag/Bi(2223) tapes
Author :
Jeremie, A. ; Flukiger, R. ; Seibt, E.W.
Author_Institution :
Dept. de Phys. de la Matiere Condensee, Geneva, Switzerland
fDate :
7/1/1994 12:00:00 AM
Abstract :
An extensive study of the detrimental effect of C on critical current densities (Jc) of Ag sheathed Bi(2223) tapes has been carried out. High Jc ran only be obtained if the C content is kept to a minimum. Successive calcination steps at 820°C are effective in reducing the amount of C in the resulting powders. On the other hand, high energy milling increases the amount of C in the powder. Controlled quantities of C impurities were introduced into the powders by performing the calcinations in a CO2 rich atmosphere. The Jc measured on tapes obtained with C-rich precursors are lower by a factor of 2 to 4 than the Jc of tapes from powders calcined in air
Keywords :
bismuth compounds; calcium compounds; carbon; composite superconductors; critical current density (superconductivity); heat treatment; high-temperature superconductors; impurities; powder technology; silver; strontium compounds; 820 C; Ag; Ag sheathed Bi(2223) tapes; Ag/Bi(2223) tapes; Bi2Sr2Ca2Cu3O10:C-Ag; Jc; calcination; controlled carbon impurities; critical current densities; high energy milling; powders; Calcination; Critical current density; Current measurement; Density measurement; Heat treatment; Impurities; Milling; Powders; Technical Activities Guide -TAG;
Journal_Title :
Magnetics, IEEE Transactions on
