Spread of critical currents in thin-film YBa/sub 2/Cu/sub 3/O/sub 7-x/ bicrystal junctions

A spread of the critical currents in a series array of up to 100 YBa/sub 2/Cu/sub 3/O/sub 7-x/ bicrystal junctions has been studied by Laser Scanning Microscopy. The values of the critical current I/sub c/ of individual junctions in the array have been obtained by focusing a laser beam on each junction and measuring the current at which the maximum laser-induced voltage response /spl Lambda/V on the array has appeared. The distribution of critical currents in logarithmic scale was close to a Gaussian one. The I/sub c/-spread has been found to increase with the increase of misorientation angle of bicrystal substrate and the decrease of the width of the junctions in the array.