Spread of critical currents in thin-film YBa sub(2)Cu sub(3)O sub(7-x) bicrystal junctions and faceting of grain boundary

A spread of the critical currents in a series array of 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 through the array at which the maximum laser-induced voltage response has appeared on the array. 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. copyright 2002 Published by Elsevier Science B.V.