Effect of furnace atmosphere on the high-TSUBc/SUBBi(Pb)-Sr-Ca-Cu-O superconductor

摘要

Bi-Sr-Ca-Cu-O superconducting phases are found to be extremely sensitive to furnace atmosphere. Experiments have been conducted in still air and flowing air, oxygen, nitrogen and argon. Air atmosphere is found best suited for the high-Tcphase. Two A-face centred tetragonal phases, one with a=5.3855AA, c=24.463AA, c/a=4.542and the other with a=5.380 AA, c=30.702AA, c/a=5.707, are recognised in the samples depending upon the composition and heat treatment.