Sequential electron beam evaporation of YBCO thin films through the barium fluoride route

摘要

Superconducting YBCO thin films have been fabricated by sequential electron beamevaporation of metallic constituents for yttrium and copper while barium is replaced with BaF2.Theconversion of BaF2→BaO has been attained through wet oxygen annealing. Correlations of stoichiometrywith microstructural. as well as superconducting, properties of the films have been examined. Results aregiven for YBa2Cu3O7-δthin films on SrTiO3(100) and YSZ(100) single crystal substrates. The usefulness ofthe BaF2 preparation route for the fabrication of mixed phase (Y123+Y124) and pure Y124 is alsodemonstrated. Microstructural properties of Y123 thin films indicate different growth processes for the twosubstrates.