Layer-by-Layer Growth of Bi-Sr-Ca-Cu-O Superconducting Films by Molecular Beam Epitaxy

Abstract
Layer-by-layer growth of Bi2Sr2Ca n-1Cu n O x oxide superconducting films by molecular beam epitaxy (MBE) have been confirmed by observation of intensity oscillations in the reflection high-energy electron diffraction (RHEED) patterns. The period of one oscillation corresponded to a growth time of a half unit cell. The films have been prepared by a coevaporation technique, In which the Bi, Sr, Ca and Cu metal sources were evaporated simultaneously with Knudsen cells under an oxygen/ozone mixture (ozone content of 10%) atmosphere. The 2212 phases fabricated exhibited critical temperatures below 70 K.