Improved microstructure of superconducting Y-Ba-Cu-O films deposited on LaAlO3substrates

Thin Y-Ba-Cu-O films with very good structural and superconducting properties have been successfully prepared on single crystal cubic LaAlO3substrates by DC magnetron sputtering and by chemical spray deposition. Reported films are substantially less granular with respect to those grown by the same method on “classical” ZrO2or MgO substrates. Microstructure properties were evaluated by microwave emission tests and microscopic structural investigations. The LaAlO3crystal has a relatively small dielectric constant and low high frequency losses, as opposed to the widely reported SrTiO3substrate, and is a promising substrate material for growing high quality epitaxial high-Tcsuperconducting films for microwave applications.