Superconducting Thin Films of “Infinite-Layer” Sr1-xNdxCuOy Synthesized by Pulsed-Laser Deposition

Abstract
Sr1-x Nd x CuO y thin films were grown on SrTiO3 substrates by a pulsed-laser deposition technique. The laser-deposited films of Sr1-x Nd x CuO y with x≦0.075 were single phase of the “infinite-layer” structure. The lattice parameter c decreased and the lattice parameter a increased, as the Nd content, x, increased. The largest value for the a-axis length did not exceed that reported for superconducting bulk samples. The expansion of the a-axis as x increased was apparently hindered by lattice dimensional mismatch between film and substrate. The films with x=0.10 and 0.125 had onset temperatures of superconducting transition around 26 K. Weak Meissner signals were observed at temperatures below 30 K.