Structural and magnetic properties of Co-doped (La,Sr)TiO3 epitaxial thin films probed using x-ray magnetic circular dichroism

We report a study of Co-doped La0.37Sr0.63TiO3−δ thin films grown by pulsed laser deposition in various oxygen pressure conditions. X-ray absorption spectroscopy and magnetic circular dichroism measurements at the Co L2,3 edges reveal that the cobalt mainly substitutes for the titanium and is in an ionic state. Nevertheless, in some films, indications of additional cobalt metallic impurities were found, suggesting that the intrinsic character of this magnetic system remains questionable.