PREPARATION OF AG-COATED SUPERCONDUCTING BI2SR2CACU2OX GLASS-CERAMIC FIBERS

The Ag-coated superconducting Bi2 Sr2 CaCu 2 Ox glass-ceramic fibers were successfully prepared. The glass fibers with a length of 50 cm, a width of 100-200 μm, and a thickness of about 20 μm were first drawn from glass plates with a thickness of 1 mm and then silver pastes were coated on the smooth surface of glass fibers. The Ag-coated glass fibers were converted into superconductors after annealing at temperatures of 820-860 °C. The main crystalline phase in the glass-ceramic fibers was the superconducting low Tc phase. The Ag-coated glass-ceramic fibers obtained by annealing at 840 °C for 5 h in air exhibited superconductivity with a Tc (zero)=70 K and a critical current density (60 K, zero magnetic field) of more than 40 A/cm2.