Flexible superconducting whiskers of the Li-doped Bi-Sr-Ca-Cu oxide

Flexible Li-doped Bi-Sr-Ca-Cu-O superconducting whiskers have been prepared by heating a glassy melt-quenched plate in a stream of O2 gas. The whiskers show a resistance drop at 110 K with a zero resistance at 81 K. These values are higher than those of the Pb-doped Bi-Sr-Ca-Cu-O whiskers by 5 and 11 K, respectively. The doping of Li is effective to raise Tc for both the 2212 phase and the 2223 phase. The Jc values of the Li-doped whiskers are 30 000 A/cm2 at 77 K and 300 000 A/cm2 at 66 K in a zero magnetic field.