In Situ Preparation of Superconducting Bi₂Sr₂Ca_n-1Cu_nO_y (n=1∼5) Thin Films by Molecular Beam Epitaxy Technique

Abstract

Superconducting Bi 2 Sr 2 Ca n -1 Cu n O y ( n =1∼5) thin films have been prepared in situ by molecular beam epitaxy with highly condensed ozone as oxidizing gas. All films including thermally metastable phases of n =4 and 5 were obtained by sequential shutter control, and even the n =1 phase film showed superconductivity. The surface of the n =1 phase film was observed by reflection high-energy electron diffraction, and the modulated structure was clearly observed.