CHARACTERIZATION OF EPITAXIAL BI2SR2CACU2O8-FILMS(DELTA THIN)

We report a dc sputtering method for the full in situ preparation of B i2Sr2CaCu2O8+delta thin films on SrTiO3 and LaAlO3. T(c) values of mor e than 90 K can be achieved by oxidizing annealing below the melting p oint, followed by a reducing anneal at 500-degrees-C. The structural p roperties of the films are revealed by X-ray diffraction in Bragg-Bren tano geometry (strong c-axis orientation with FWHM (0 0 10) = 0.3) and also by PHI scans (epitaxy within the substrate plane). Rutherford ba ckscattering and channeling confirmed the correct composition of the c ations while the minimum yield, chi(min), is 23%. Depth profiles by SN MS show a very homogeneous distribution of the cations with no detecta ble loss of bismuth near the surface. The surface morphology of the fi lms was studied by SEM and by STM. Patterning of the films in lateral geometry can be performed by photolithographic techniques without degr adation of T(c).