This paper reports the fabrication of a-axis oriented YBa2Cu3O x /PrGaO3 insulating barrier/a-axis oriented YBa2Cu3O x trilayer films by in-situ pulsed-laser deposition. A cross sectional transmission electron microscopy (XTEM) analysis of the junctions verifies that the ultrathin PrGaO3 insulating barrier does not form islands between the base and the counter electrode of YBa2Cu3O x films and the a-axis oriented YBa2Cu3O x grows right on the insulating PrGaO3 ultrathin (30 Å) film without any c-axis oriented or disordered YBa2Cu3O x layer. Excellent surface coverage of the base electrode of the YBa2Cu3O thin film is considered to result from lattice matching and the similarity of the crystal structure. Lattice matching perovskite insulators with the same thermal expansion coefficient are attractive for use as the insulating barrier for superconductor/insulating barrier/superconductor (SIS) junctions.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)