Electron-doped superconductivity induced by oxygen vacancies in as-grown Sr_0.6Ca_0.4CuO₂infinite-layer films

Abstract

Thin films of the infinite-layer compound Sr0.6Ca0.4CuO2−δ have been prepared by off-axis rf magnetron sputtering on SrTiO3 (001). For an optimum level of oxygen vacancy superconductivity was observed (Tc onset = 42 K and Tc(ρ = 0) = 11 K). Structural and transport data suggesting n-type superconductivity are presented and discussed. Infinite-layer thin films of Sr0.6Ca0.4CuO2−δ, without trivalent cation doping and showing n-type superconductivity, are reported for the first time.