Particle-free superconducting Bi 2Sr 2CaCu 2O x ultrathin films prepared by atomic-layer-controlled molecular beam epitaxy technique

Abstract

Atomic-layer-controlled molecular beam epitaxy (ALC-MBE) technique is applied for preparing Bi 2Sr 2CaCu 2O x ultrathin films. Precise control of the composition by ALC-MBE enables successful growth of particle-free ultrathin films. Superconducting zero-resistance transitions are observed for the films more than 3.0 nm in thickness. It is also shown that growth of a Bi 2Sr 2CuO y buffer layer between the film and SrTiO 3(100) substrate contributes to preparing such particle-free ultrathin films with good superconducting properties.