Fabrication of (Cu, C)Ba₂CuO_<i>y</i> superconducting thin film by RF magnetron sputtering

Abstract

We report the superconducting properties of (Cu, C)Ba2CuOy thin films deposited by RF magnetron sputtering from targets with a nominal composition of Ba2Cu1.5Oy. The thin films were grown in mixed Ar (5∼40 mTorr), O2 (0∼1.2 mTorr) and CO2 (0∼1.8 mTorr) atmosphere. The epitaxial c-axis oriented thin films with c-axis length in the range between 7.96 Å and 8.82 Å were obtained on SrTiO3(100) substrates, but superconductivity was observed only for the films which have the c-axis length with 8.01 Å and 8.32 Å. By optimizing deposition conditions, the excellent (Cu, C)Ba2CuOy thin film with Tc = 62K and superconducting transition width ΔTc = 1.5 K was successfully obtained.