PREPARATION OF BISRCACUO SUPERCONDUCTING THIN-FILM BY MOLECULAR-BEAM EPITAXY WITH NO2

A BiSrCaCuO superconducting thin film was prepared in situ by molecular beam epitaxy with nitric dioxide gas (NO2). Metal sources were coevaporated onto the MgO (100) substrate at the substrate temperature of approximately 700-degrees-C under the background pressure of the growth chamber of approximately 5 x 10(-6) Torr. The deposition speed was approximately 1.8 angstrom/s and the thickness of the thin film was approximately 3000 angstrom. The zero resistance was obtained at 65 K without the annealing steps. The quality of the BiSrCaCuO superconducting thin film prepared with NO2 is comparable to that prepared with distilled ozone under identical growth condition except for the distilled ozone flux intensity. Oxidation behaviors of NO2 were studied and are compared with those of distilled ozone.