As nowadays the evolution of global warming is persistent, the development of alternative energy sources together with efficient energy transport is essential. Undoubtedly, the discovery of high temperature superconductors (HTS) proved to be an appealing solution to enhance importantly clean electrical energy, but the high production costs of the currently available technology are keeping it from its worldwide spread. The feasibility of low cost nanostructured epitaxial cuprate superconductors has been demonstrated by implementing chemical solution deposition (CSD) techniques. Thus, we present a versatile and tunable CSD method suitable for the preparation of epitaxial YBa₂Cu₃O₇ superconducting films. Focusing solely on fluorine-free solutions, not only we are meeting the global requirement for greener chemical processes compared to the renowned TFA route, but at the same time we are able to achieve ultrafast growth rates beyond 100 nm/s by using transient liquids during the epitaxial growth of the superconducting layer in the innovative framework of TLAG (transient liquid assisted growth), a high-throughput scalable process [1], making it interesting for industrial applications. Hence, solutions of different Ba/Cu molar ratio are prepared to modify the supersaturation and characteristics of the transient liquid, using a facile and fast method from home-synthesized Y, Ba, and Cu propionates precursors, reaching endured solution stability, thickness tunability and high homogeneity. Employing in-situ XRD synchrotron radiation and HRTEM/STEM, the distinct liquid compositions provide us with a wide understanding of the TLAG process opportunities, kinetic phase diagram, and a strong correlation between superconducting performance properties and unique characteristics of each liquid composition, easily tuned through solution chemistry.

[1] Soler, L., Jareño, J., Banchewski, J. et al. Ultrafast transient liquid assisted growth of high current density superconducting films. Nat Commun 11, 344 (2020). https://doi.org/10.1038/s41467-019-13791-1

Keywords: transient liquid assisted growth, chemical solution deposition, YBCO, supersaturation