Evolution of Oriented Structures in YBa2Cu3O7-(delta) Films by Liquid Phase Epitaxy through Manipulating Supersaturation

The preparation of YBa2Cu3O7-delta (YBCO) films with different crystallographic orientations is of significant importance for superconductor studies and applications. Here, we systematically investigated the correlation between the film orientation and the supersaturation (sigma) state in liquid phase epitaxy, using a fine-tuning technique and adjusting a supplementary solvent material (its melting time Delta t(m)). Our findings show that Delta t(m) functions as a key factor, possessing a wide tuning range for subdividing supersaturation. We attribute this to the time-consuming characteristic in altering the saturation level, related to solute dissolution and diffusion phenomena. Consequently, the continuous transition of oriented structures in YBCO films becomes controllable by subtle manipulation of sigma. It is worth emphasizing that the tunable alignment of a-oriented grains in c-oriented YBCO films was effectively achieved, which has not been successful by conventional techniques.