Mecanism de creştere şi proprietǎţi ale filmelor subţiri de YBa₂Cu₃O_7-αdepuse prin ablaţie laser PE (001) SrTiO₃

High quality, single phase c-axis oriented YBa₂Cu₃O_7-α thin films with superconducting properties were grown by laser ablation on (001) SrTiO₃ substrates. The surface morphology of the films has been investigated by means of high-pressure reflection high energy electron diffraction (RHEED), atomic force microscopy (AFM), and scanning electron microscopy (SEM), while the structural properties were studied by X-ray diffraction (XRD). Deposition under optimum conditions produces films with relatively smooth surface, with a roughness of about 10-15 nm, as confirmed by AFM and SEM data. The growth follows a Stransky-Krastanov mechanism governed by the substrate-film interface properties due to presence of epitaxial strain. The films show good superconducting properties with T_c values of 85-91 K. Results on the fabrication and electrical transport properties of ramp-type Josephson junctions with YBa₂Cu₃O_7-α electrodes and PrBa₂Cu₃O_7-α barrier are presented.