Y-Ba-Cu-O superconducting fibers and wires by spray pyrolysis on carbon fibers

Superconducting YBa2Cu3O7-x fibers and wires have been prepared by spray pyrolysis of metal nitrate precursors on a commercial carbon fiber substrate, followed by heating in air and annealing in O2. The fibers were characterized by x-ray diffraction, scanning electron microscope, and Tc and Jc measurements. The fibers consisted of well-aligned crystals and no carbon, with a Tc (zero) of 82 K and a Jc of 2150 A/cm2 in zero field. Ag-doped fibers were fabricated by adding AgNO3 in the precursor solution, and the Jc value nearly doubled with the addition of 4 wt. % Ag