In this paper, oxygen-deficient $\mathrm{L}{\mathrm{a}}_{0.67}\mathrm{S}{\mathrm{r}}_{0.33}\mathrm{Co}{\mathrm{O}}_3$ (LSCO) thin films are prepared by adjusting the oxygen pressure during the deposition. As oxygen vacancies are introduced into the LSCO films, the out-of-plane lattices are elongated, as revealed by x-ray diffraction and high-resolution transmission electron microscopy (HRTEM). Modulated bright and dark stripes observed in the HRTEM images of the oxygen-deficient LSCO films are induced by cation ordering and oxygen vacancy ordering, respectively. Magnetic measurements and first-principles calculations show that the oxygen vacancies depress the magnetism of the LSCO films greatly. We also demonstrate that doping Sr into $\mathrm{LaCo}{\mathrm{O}}_3$ and removing oxygen from LSCO have a similar effect on the magnetic properties, which is correlated with a derived formula.

• Received 21 November 2015
• Revised 3 January 2016

DOI:https://doi.org/10.1103/PhysRevB.93.094421