Preparation of Compositionally Modulated Bi-Sr-Ca-Cu-O Multilayered Films by Plasma Controlled Sputtering

Abstract
A plasma controlled sputtering method was applied to the continuous deposition of compositionally modulated Bi-Sr-Ca-Cu-O films on MgO substrates. In this method, the target area to be sputtered can be controlled by varying the distribution of magnetic field above the binary target composed of an inner SrCaCu2O y plate and an outer Bi metal ring. The designed layer periodicity agreed well with that measured by the low-angle X-ray scattering. The postannealing of a deposited multilayered film at 890°C for 10 h in air made it superconducting with onset and zero-resistivity temperatures at 110 K and 72 K, respectively.