Tunneling through grain boundaries of YBa2Cu3O7stephyphen;edge junctions

摘要

Tunneling experiments were done on YBa2Cu3O7stephyphen;edge junctions. The temperature dependence of the superconducting gap parameter, Dgr;(T), was measured. From the peakhyphen;tohyphen;peak distance in the conductance curve, Dgr; was estimated to vary from 24 to 32 meV at 4.2 K. The conductance at highhyphen;voltage bias does not increase with increasing voltage. The tunneling results, together with the wellhyphen;behaved magnetic field dependence of the critical Josephson current, hysteresis, and Fiskehyphen;type resonances in currenthyphen;voltage curves, indicate a dielectric behavior of the grain boundary junction, i.e., a tunnel junction. copy;1996 American Institute of Physics.