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

High-quality c-axis-oriented YBa2Cu3O7-delta (YBCO) films were prepared using the laser ablation method. Films with a full width at half-maximum 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% were obtained by optimizing the experimental conditions. The atomic image and superconducting gap at 4.2 K were simultaneously observed for the first time on these high-quality YBCO films by scanning tunneling microscopy 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 significant deterioration in superconductivity at the film surface.