Microstructure of sputtered superconducting films of Bi2Sr2CaCu2Ox made by low-temperature, in situ growth.

摘要

Superconducting films of Bi(sub 2)Sr(sub 2)CaCu(sub 2)O(sub x) have been sputtered onto single crystal MgO substrates using an in situ process at a substrate temperature of (approximately)645(degree)C. These c-axis oriented films exhibit an extrapolated T(sub c0) of 56 K. Electron microscopy reveals that the films are not smoother than films which were post-annealed at 865(degree)C, and that segregation and second-phase precipitation had occurred. It is evident that surface diffusion during in situ processing can enhance segregation in Bi(sub 2)Sr(sub 2)CaCu(sub 2)O(sub x) films. 7 refs., 7 figs.