ROLE OF HALOGEN DOPANTS IN AG-Y1BA2CU3O7-X COMPOSITES

The influence of halogen doping on the Ag-Y1Ba2Cu3O7-x superconducting composite has been investigated. It is seen that exposing the Y1Ba2Cu 3O7-x (YBCO) to bromine prior to mixing with silver increases the crit ical current density of the composite significantly despite a simultan eous increase in porosity. Therefore, if the porosity can be suppresse d, the beneficial effect of halogen doping can be further enhanced. Th is dopant also tends to increase the average particle size, i.e. decre ase the interface/volume ratio in the system. These results open up th e possibility of using halogen doping as a very simple, yet effective step in improving the electrical transport at superconductor interface s.