Deposition of superconductive YBaCuO films at atmospheric pressure by RF plasma aerosol technique

Superconducting Y1Ba2Cu3O7−δ films were produced by a radio frequency (RF) plasma aerosol evaporation technique at atmospheric pressure without post‐annealing. Aqueous solutions containing Y, Ba, and Cu were genertaed as an aerosol which was then injected into the plasma region. The ionized species were deposited onto substrates outside of both the plasma and flame regions. The substrate temperature was 400–600°C. The deposition rate is 0.01–100 μm/ (min cm2), and the film thickness is 1–200 μm. For an ‘‘as deposited’’ film on a single crystalline MgO substrate (100) with substrate temperature of 600 °C, the onset temperature of the superconducting transition is 100 K with a transition width (10%–90%) of 3 K, and zero resistance at 93 K. The critical current density of the film is 0.8–104 A/cm2 at 77 K. An optimum substrate temperature for this technique is discussed. The as‐deposited films are compared with other post‐annealed films (850°C, 1 hour). Since this technique does not require a vacuum environm...