The superconducting fibrous crystals of Bi(Pb)-Sr-Ca-Cu-O (2212 phase) have been prepared by heating a glassy melt-quenched plate in an oxygen atmosphere. The crystals show Tc(onset) at 75 K and Tc(end) at 70 K. The fibers have a single crystal nature and can be bent to a radius of curvature (R) of 0.4 mm without a decrease in the Tc value. The highest Jc is 67000 A/cm2 (63 K, zero magnetic field) in a nonbending state. It surpasses 35000 A/cm2 even in a bending state of R>1 mm and finally decreases down to 3200 A/cm2 for R=0.4 mm.

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The upper critical field (H, 2) of the 110-K Bi,Sr,Ca2Cu30 phase has been obtained using high-quality whiskers and the measurement of the field-induced resistive transition up to 7.5 T. In the presence of magnetic fields parallel and perpendicular to the c axis, linear relations are obtained in H, 2-T curves defined at the 50%%uo value of the extrapolated normal-state resistivity in the transition curves. According to the Werthamer-Helfand-Hohenberg theory and Ginzburg-Landau relations, the coherence lengths of 0 0 g,~( 0) = 29 A and g, (0)=0.93 A are obtained. The anisotropy ratio of the coherence length is 31.

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.

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