Josephson modulations of critical current above 77 K in YBa2Cu3O7–Au thin film composites grown on LaAlO3

Abstract Composite films of YBa 2 Cu 3 O 7 –Au were grown on LaAlO 3 substrates using a sequential bilayer deposition process with different thickness of the Au layer. A reproducible and clear Josephson effect was observed only when the composite exhibited a labyrinth-like microstructure. Magnetic field modulation of the critical current was obtained at temperatures above 77 K. In this case gold-rich islands constrained weak-link zones, which conduced to a quasi-controlled array of Josephson junctions in the composite.