Preparation of Ag‐coated superconducting Bi2Sr2CaCu2Ox glass‐ceramic fibers

The Ag‐coated superconducting Bi2 Sr2 CaCu2 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 .