JOINING OF HIGH-CURRENT BULK Y-BA-CU-O SUPERCONDUCTORS

A new fabrication method which makes it possible to enlarge the size of small, but high quality, grain-aligned superconductors has been developed. This method involves solid state joining of high current density bulk YBa2Cu3Ox samples prepared by melt-processing. The joined samples exhibit superconductivity above 90 K and are found to be capable of carrying currents in excess of 150 A at 77 K. The interface of the joined samples is found to sustain current densities (J(c)) in excess of 6000 A/cm2 at zero field and in excess of 4000 A/cm2 at 1.5 T. Also, the magnetic field dependence of J(c) of the joined samples is similar to that of the individual samples. Since this joining method is not limited by the size of the superconductors that can be joined, the favorable transport and magnetic properties render this process suitable for applications requiring high temperature superconductors in bulk forms.