Tunneling characteristics of internal josephson junctions inYBa2Cu3O7−δthin films

We have measured detailed $I-V$ characteristics of small areas of $\mathrm{Y}{\mathrm{Ba}}_2{\mathrm{Cu}}_3{\mathrm{O}}_{7-\delta }$ films, which exhibit structure associated with individual Josephson junctions within the film. Both hysteretic and nonhysteretic junctions are seen. A simple model relating the voltage steps to the junction properties is developed. The temperature dependence of $I_c$ for the hysteretic junctions fits that predicted for quasiparticle tunneling junctions between conventional superconductors.