Infinite-layer phase formation in the Ca1–xSrxCuO2 system by reactive molecular beam epitaxy

We synthesized thin films of the thermodynamically unstable infinite-layer compound Ca1–xSrxCuO2 by reactive molecular beam epitaxy and established thermodynamic boundary conditions that allow for the minimization of impurity phases and defects. In particular, the choice of radio-frequency oxygen plasma as an oxidizing agent as well as diverse substrate materials has been found to limit the stability region in a way that is comparable to the...