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Films of Y1Ba2Cu3O7-y have been grown by off-axis DC sputtering onto substrates of (100) SrTiO3. LaAlO, LaGaO3, Yttria-stabilized Zirconia, and MgO. Our best films, grown on SrTiO3 substrates at a temperature of 650°C and a sputtering pressure of 100 mTorr (consisting of 80 mTorr Ar and 20 mTorr O2) have room temperature resistivities of 280 μΩ-cm, an inductive Tcof 88 K and an inductive Jc 'Sof∼ 2.6 × 106 A/cm2 at 77 K and 3.9 × 107 A/cm2at 4.2 K. Films grown on YSZ tend to have higher resistivities (∼ 600 μΩ-cm) but still have Tc's of 86 K and Jc's of - 106 A/cm2 at 77 K. Films down to 550 Å still have Tc's of 86 K and Jc's at 77 K > 106 A/cm2. Films grown at lower temperatures (600°C) on S1TiO3 begin to show a-axis growth, but the superconducting properties deteriorate.

We have grown thin film composites of and YBa2Cu3O7−x and LaAlO3 by co-sputtering. A film with composition of 10% LaAIO3 by volume had a transition temperature of 58K and critical current density of 1.2 × 106 A/cm2 at 4K. We measured the temperature dependence of the critical current and obtained a good fit with Ginzburg-Landau theory for thin films. A perpendicular magnetic field was applied, and the critical current and pinning force measured. At 70 kOe, the critical current was suppressed only a factor of 4 from its zero-field value. The measured pinning force was 2 × 109 dyn/cm3 at 70 kOe and is comparable to that of YBa2Cu3O7−x films.