Characteristics of YBa2Cu3O7−x/SrTiO3/YBa2Cu3O7−x films formed by chemical solution deposition

From the perspective of practical application, chemical solution deposition (CSD) technology is promising for the preparation of superconductor/insulator/superconductor (SIS) junctions with YBa2Cu3O7−x films as the superconducting layers compared with the various vacuum deposition processes currently used. In this study, trilayer films of YBa2Cu3O7−x/SrTiO3/YBa2Cu3O7−x were prepared using the CSD method. It was observed that when the nominal thickness of the interlayer (SrTiO3) was 14 nm, the I-V curve of the structure was similar to that of a weak-link Josephson junction due to the predominant weak links of microbridges and point contacts. When the nominal thickness of the interlayer was 40 nm, the I-V curve exhibited hysteresis due to the predominant tunnel effect. When the nominal thickness of the interlayer was 120 nm, the various weak links for superconducting coupling were absent, and the resistivity between the two YBa2Cu3O7−x layers was 3.4×107 Ω cm, which can satisfy the requirements for isolating electrodes in superconducting electron devices.