Optimization of a fluorine-free metal-organic deposition to fabricate BaZrO 3 -doped YBa 2 Cu 3 O 7−δ film on RABiTS substrates

In this study, we used a systematic route to optimize the fluorine-free MOD process to achieve a high critical current density ( J c ) in BaZrO 3 (BZO)-doped YBCO films on RABiTS substrates. The BZO content is given by 1 YBCO+ x BZO films, where x is moles of BZO per 1 mole of YBCO. We found x = 0.10 to be the optimal BZO content and ∼795–805 °C to be the optimal growth temperature window with 60–90 min processing time. TEM studies show the BZO nanoparticles are ∼20 nm in size and spaced ∼50–100 nm apart. The in-field J c and the peak pinning force ( F p ) of the film grown at the optimal conditions were greatly increased at 77 K relative to pure YBCO films, achieving ∼6.7 GN m −3 at 77 K, H || c in a ∼800 nm thick x = 0.10 film. The angular dependence of in-field J c measurements also shows greatly reduced angular anisotropy at 1 and 4 T at 77 K due to isotropic pinning by BZO nanoparticles.