Reduction and oxidation of SrCoO2.5 thin films at low temperatures

Brownmillerite SrCoO2.5 (010) thin films synthesized by pulsed laser deposition became amorphous when reduced at low temperatures by CaH2, indicating that the infinite-layer structure with the square planar Co2+O4 configuration is unstable. Ferromagnetic and conducting perovskite SrCoO3 epitaxial thin films, on the other hand, were obtained topotactically at room temperature by oxidation with NaClO.