Composition Dependence and Electrical Properties of Tc>100 K BiSrCaCuO Superconducting Oxide Films Prepared by Sequential Deposition

Abstract
Preparation of BiSrCaCuO superconducting oxide films with T c>100 K was investigated by a sequential deposition technique. The nominal composition exhibiting T c>100 K ranged from 1112 (Bi:Sr:Ca:Cu=1:1:1:2) to 1312, although a volume fraction of the high-T c phase evaluated by X-ray and magnetic susceptibility measurements was less than 10% at most. A characteristic feature of the films with T c>100 K was that extrapolations of normal resistance always intersected the temperature axis on the positive side. The temperature dependence of the Hall coefficient for these films is also described briefly.