Electrical characteristics of HoBa2Cu3O7-x-PrBa2Cu3O7-y-HoBa2Cu3O7-x junctions with planar-type structures

All-oxide superconductor-normal conductor-superconductor (S-N-S) junctions with a planar-type structure are fabricated using HoBa2Cu3O7-x and PrBa2Cu3O7-y as the superconductor and normal conductor, respectively. Their electrical characteristics are measured. The junction's normal resistance is almost comparable to that of a single PrBa2Cu3O7-y film. However, it deviates from the T-1/3 (T is temperature) law and saturates at low temperatures for junction lengths smaller than 1.0 μm. Superconducting characteristics obtained for this type of junctions may be accompanied by this saturation of normal resistance. Nonlinear current-voltage characteristics that may reflect correlation energy in the PrBa2Cu3O7-y layer are also detected. (orig.)