Critical current in silver clad Y-Ba-Cu-O superconducting wires

Silver clad wires of highT _c superconductor Y₁Ba₂Cu₃O_7−x have been fabricated through the powder metallurgy technique. The reacted wires show a midpointT _c of 84K. A critical current density of 26·4 A cm⁻² (77K, 0T) is obtained in these wires. The wires, however, turn complete normal only at a current density of 280 A cm⁻². The reasons for low critical current density obtained in these wires are discussed.