Preparation of As-Deposited Bi-Sr-Ca-Cu-O Films with High T_c Superconducting Phase by Metalorganic Chemical Vapor Deposition

Abstract

As-deposited Bi-Sr-Ca-Cu-O films with the high T c phase were prepared on MgO (100) substrates by metalorganic chemical vapor deposition using triphenyl bismuth and β-diketonates of Sr, Ca and Cu as source materials. Films with a superconducting onset temprature of 110 K and a zero resistance temperature of 70 K were obtained at 800°C without postannealing. The X-ray diffraction patterns show that the films consist of the high T c single phase with the c -axis oriented normal to the substrate surfaces. The surface structures of the films were found to be much smoother than those of postannealed ones.