A thick film (~1 µm) of (Hg, Re)-1223 precursor has been deposited on a substrate at high temperature (800 °C) from an aerosol. The mercuration is then performed ex situ in a sealed quartz ampoule. This forms a (Hg, Re)-1223 superconducting film of optimum Tc (133 K) without post-annealing oxygen processes. The film is c-axis textured. The total process is fast and low cost and could be easily scaled up.

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Spray pyrolysis at high temperature is reviewed and applied to the formation of epitaxial thick layers of YBa 2 Cu 3 O 7 (YBCO). The necessary conditions to enhance the texture quality and the critical current density are discussed. High critical current densities, over 1.0 MA cm −2 (at 77 K, self-field), are reported, making this technique very promising for low cost applications. This emphasizes the need for more comprehensive studies regarding the chemical phenomena involved in film deposition by spray pyrolysis at high temperature, especially those concerning local equilibrium and reactions occurring in the area involved in the deposition.

Abstract. Thick films of the high temperature T1Ba2Ca2Cu30, superconductor have been prepared from a precursor Ba2Ca2Cu30, obtained by spray pyrolysis. In this paper, we report on the parameters which mainly control the formation of the superconducting phase: the composition of the nitrates solution, the substrate temperature and the subsequent ex-situ thallination annealing. The sample were analyzed by X-ray diffraction and by secondary electron microscopy. Epitaxial film ( 1 to 2 pm thick ) with a critical temperature Tc=107 K and a critical density of current J,(77 K, 0~) = 2 . 1 0~ ,Wcm2 have been obtained.