Reactive ion beam deposition of thin films in the bismuth-calcium-strontium-copper oxide ceramic superconductor system

Abstract

Reactive ion beam deposition has been used to grow c-axis-oriented superconducting thin films in the Bi-Ca-Sr-Cu-O (BCSCO) system around the cation ratio 1:1:1:1 on single-crystal (001) MgO. The films show a single superconducting transition with an initial onset near 85 K and a critical current of 5×104 A/cm2 at 10 K. Two different BCSCO-containing phases have been identified in the thin films: one with a tetragonal pseudo-body-centered subcell, c=24.4 Å, which is not superconducting above 28 K, and a second with c=30.6 Å, which is responsible for the superconductivity. Electron diffraction measurements on the 30.6 Å phase are consistent with those previously reported for the bulk ceramic.