Modification of step-edge grain boundary Josephson junctions by electromigration

We report on the effects of large electric currents (>2 MA/cm/sup 2/) applied at /spl sim/300 K to step-edge thin-film microbridges of YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta//. These step-edge Josephson junctions showed an increase in their critical current (I/sub c/) after application of electromigration current, I/sub EM/. This increase of I/sub c/ was a permanent phenomenon. Electromigration was also performed on SNS YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// thin-film microbridges and an increase in critical current was observed.<
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