Preparation of BiSrCaCuO Superconducting Thin Film by Molecular Beam Epitaxy with NO₂

Abstract

A BiSrCaCuO superconducting thin film was prepared in situ by molecular beam epitaxy with nitric dioxide gas (NO 2 ). Metal sources were coevaporated onto the MgO (100) substrate at the substrate temperature of ∼700°C under the background pressure of the growth chamber of ∼5×10 -6 Torr. The deposition speed was ∼1.8 Å/s and the thickness of the thin film was ∼3000 Å. The zero resistance was obtained at 65 K without the annealing steps. The quality of the BiSrCaCuO superconducting thin film prepared with NO 2 is comparable to that prepared with distilled ozone under identical growth condition except for the distilled ozone flux intensity. Oxidation behaviors of NO 2 were studied and are compared with those of distilled ozone.