MOD-Derived YBa2Cu3O7-δ Thin Films using a Fast Pyrolysis Process

In the present work, a fast pyrolysis process is developed for YBa2Cu3O7-δ (YBCO) films preparation with trifluroacetates metalorganic deposition technique (TFA-MOD). The decomposition of TFA salts as well as the surface morphology of pyrolyzed films is investigated with respect to the pyrolysis temperature and its heating rate. Two typical surface morphologies for the pyrolyzed films, being smooth or buckled, are revealed subjecting to the heating rate and film thickness, which related to the subsequent YBCO films property. Smooth and wrinkle-free pyrolyzed films are achieved by using this fast pyrolysis process with a heating rate as high as 5°C/min. The final crystallized YBCO films exhibit good performances with the superconducting transition temperature of 91 K and critical current density of 2.0 MA/cm2 at 77 K, suggesting a rapid, promising MOD route available for scale-up preparation of YBCO coated conductors.

Fabrication of Ba(Ce, Zr)0.9Y0.1O3-α Thin Film on a Dense Pd Substrate by Ultraviolet Metalorganic Deposition

The formation of dense thin films to obtain an intermediate temperature solid oxide fuel cell (IT-SOFC) that uses Ba(Ce1−xZrx)0.9Y0.1O3−α (BCZYO, x = 0, 0.3, 1) as the proton conductor was attempted on a dense Pd substrate at low sintering temperatures by the metalorganic deposition (MOD) method. A BaCe0.9Y0.1O3−α (BCYO) thin film (thickness 0.8 μm) was prepared by MOD and then annealed at 850°C on a Pd substrate with low heat resistance. However, there are problems such as the very low density of the BCYO film and the presence of a PdO interlayer between the film and the Pd substrate. The densification of the crystallized BCYO thin film, which is about 0.5-μm thick, was improved by introducing a UV-assisted MOD process. Rapid thermal annealing (RTA) eliminated the PdO interlayer. In addition, the formation of dense thin films of BCZYO was achieved by the same UV-MOD (RTA) method. Therefore, the successful application of UV-MOD (RTA) to the formation of BCZYO thin films at low sintering temperatures was established.