LINEWIDTH DEPENDENCE OF CRITICAL CURRENT-DENSITY IN Y1BA2CU3O7 THIN-FILM MICROBRIDGES

A study of the dependence of the transport critical current density (J(c)) on the width of Y1Ba2Cu3O7 thin-film microbridges with widths down to 2-mu-m has been made. No evidence of edge pinning, which leads to larger J(c)'s in narrower microbridges, was found. Due to the limitation in resolution of photolithography encountered in common usage, a tapered or radiation damaged edge was always present, which may have introduced a significant error in the cross section and hence in the estimation of J(c). By normalizing the critical current (I(c)) to the room-temperature resistance of the microbridge, we can eliminate this mask-defined cross-sectional error.