Highly oriented YBa2Cu3O7-x thin films prepared by unbalanced DC magnetron sputtering from a single stoichiometric target

Highly oriented films of YBa2Cu3O7-x have been reproducibly prepared with the correct metal stoichiometry by dc magnetron sputtering from a single target of stoichiometric composition. To circumvent the resputtering effects, the magnetron used an unbalanced magnetic filed configuration to direct the plasma away from the substrate. Typical films have sharp superconducting transitions with Tc up to 93 K and ΔTc (90%-10%) = 0.5 K, metallic resistivity above the transition with ρ300/ρ100 = 2-4, and Jc ≥ 1.5 x 106 Acm2 at 4.2 K. The temperature dependence of Jc obeys the flux creep model with activation energy U(0) = 75 meV