YBa2Cu3O7-x thin films and YBa2Cu3O7-x/CeO2 heteroepitaxial structures grown on YSZ substrates by pulsed injection CVD

The in situ synthesis of thin YBa2Cu3O7-x (YBCO) films and YBCO:CeO2 heterostructures was carried out on (001) ion mass spectrometry (SIMS) concentration profiles revealed a diffusion of Zr from the unbuffered substrate to the films. Zr(Y)O-2. (YSZ) substrates from the organometallic vapor phase by a new pulsed injection CVD technique. The secondary The films had a dominating (001) texture and a dominating 45 degrees in-plane orientation, but other orientations (0 degrees, 9 degrees, 36 degrees) were also not infrequent in the films. The vapor phase composition was found to have a great influence on the film microstructure and critical parameters. The critical temperatures (T-c) of the best YBa2Cu3O7-x films were about 90 K, the critical current densities (J(c)) being similar to 4 x 10(5) A cm(-2) at 77 K, A thin epitaxial CeO2 layer grown in situ before YBCO deposition stopped the Zr diffusion from the substrate and dramatically improved the epitaxy and critical parameters of YBCO films. The T-c (Delta T-c) and J(c) of the deposited YSZ/CeO2/YBCO heteroepitaxial structures equaled similar to 90 K (similar to 0.3 K) and similar to 4 x 10(6)A cm(-2) at 77 K. This result shows that a simple deposition of an intermediate CeO2 layer before the growth of YBCO makes YSZ substrates very competitive with perovskite substrates.