The role of the silver intermediate layer in the YBa2Cu3O7−x/Ag/ In2O3/Si system

Abstract Superconducting YBa 2 Cu 3 O 7− x (YBCO) thin films were deposited on Si(111) substrates with a conductive intermediate layer of Ag In 2 O 3 . In 2 O 3 was prepared by the d.c. magnetron method and a silver thin film was evaporated on the In 2 O 3 /Si(111). The YBCO thin films were deposited by d.c. magnetron sputtering. The conductive In 2 O 3 thin film was used to minimize the interdiffusion between silicon and the YBCO superconducting material. The silver thin film improves the zero-resistance temperature, transition temperature width, and the critical current density of the superconducting YBCO film in the YBCO/In 2 O 3 /Si system. Films of YBCO on the Ag/In 2 O 3 /Si substrate have zero resistance at 85 K and a critical current density of 2.0 x 10 3 A cm −2 at 77 K. The XRD spectrum indicates that the superconducting thin films have a preferential c axis oriented structure. Auger electron spectroscopy depth profiling was used to analyse the interfaces.