Properties of the electron-doped infinite-layer superconductor Sr$_{1-x}$La$_{x}$CuO$_{2}$ epitaxially grown by pulsed laser deposition

Abstract

Thin films of the electron-doped infinite-layer cuprate superconductor Sr$_{1-x}$La$_x$CuO$_2$ (SLCO) with doping $x \approx 0.15$ were grown by means of pulsed laser deposition. (001)-oriented KTaO$_3$ and SrTiO$_3$ single crystals were used as substrates. In case of SrTiO$_3$, a BaTiO$_3$ thin film was deposited prior to SLCO, acting as buffer layer providing tensile strain to the SLCO film. To induce superconductivity, the as-grown films were annealed under reducing conditions, which will be described in detail. The films were characterized by reflection high-energy electron diffraction, atomic force microscopy, x-ray diffraction, Rutherford backscattering spectroscopy, and electric transport measurements at temperatures down to $T = 4.2\,$K. We discuss in detail the influence of different process parameters on the final film properties.