PREPARATION AND NANOSCALE CHARACTERIZATION OF HIGHLY STABLE YBA2CU3O7-DELTA THIN-FILMS

High-quality c-axis-oriented YBa2Cu3O7-delta (YBCO) films were prepare d using the laser ablation method. Films with a full width at half-max imum of the (005) X-ray diffraction peak as narrow as 0.1-degrees and an chi(min) of Rutherford backscattering spectrometry as low as 3.5% w ere obtained by optimizing the experimental conditions. The atomic ima ge and superconducting gap at 4.2 K were simultaneously observed for t he first time on these high-quality YBCO films by scanning tunneling m icroscopy and scanning tunneling spectroscopy. Such observations, even after the film was stored in air for three weeks, indicates that YBCO film is sufficiently chemically and physically stable to prevent sign ificant deterioration in superconductivity at the film surface.