Preparation of Tl-System Superconducting Thin Films by the Mist Microwave-Plasma Chemical Vapor Deposition Method

Abstract

Superconducting thin films of Tl–Sr–Ca–Cu–O were prepared on single-crystal MgO(100) substrates by the mist microwave-plasma chemical vapor deposition method, and the dependence of Tc-zero of films on the input molar ratio of oxygen OR=FO2 /(FO2 +total FAr) was investigated. In addition, the effect of the Bi addition on Tl–Sr–Ca–Cu–O superconducting thin films was studied. The prepared films were constituted of the 1212 and/or 1223 phases with c-axis orientation perpendicular to the substrates. The maximum Tc-zero (zero resistance; 102 K) of as-deposited films was obtained at the input molar ratio of oxygen ( OR) of 0.30, the microwave power of 300 W and the addition amount (x= Bi/(Tl+Bi)) of 0.30.