Mehta, V. V.Biskup Zaja, NevenkoJenkins, C.Arenholz, E.Varela Del Arco, MaríaSuzuki, Y.2023-06-182023-06-182015-04-231098-012110.1103/PhysRevB.91.144418https://hdl.handle.net/20.500.14352/24036© 2015 American Physical Society. We thank Kin Man Yu for help with RBS as well as Juan Salafranca, Marco Liberati, Rajesh Chopdekar, Joanna Bettinger, Franklin Wong, Jodi Iwata-Harms, and Chunyong He. Research at UC Berkeley/LBNL and Stanford was supported by the U.S. Department of Energy, Director, Office of Science, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under Contracts No. DE-AC02-05CH11231 (Berkeley and LBNL) and No. DESC0008505 (Stanford). STEM/EELS research at ORNL (M.V.) was supported by the U.S. Department of Energy, Director, Office of Science, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering and through a user project supported by ORNL’s Center for Nanophase Materials Sciences (CNMS), which is sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy. STEM/EELS research at UCM (N.B.) was supported by the ERC starting Investigator Award, Grant No. 239739 STEMOX and Fundación Caja de Madrid.We demonstrate that a combination of electronic structure modification and oxygen vacancy ordering can stabilize a long-range ferromagnetic ground state in epitaxial LaCoO_(3) thin films. Highest saturation magnetization values are found in the thin films in tension on SrTiO_(3) and (La,Sr)(Al,Ta)O_(3) substrates and the lowest values are found in thin films in compression on LaAlO_(3). Electron microscopy reveals oxygen vacancy ordering to varying degrees in all samples, although samples with the highest magnetization are the most defective. Element-specific x-ray absorption techniques reveal the presence of high spin Co^(2+) and Co^(3+) as well as low spin Co^(3+) in different proportions depending on the strain state. The interactions among the high spin Co ions and the oxygen vacancy superstructure are correlated with the stabilization of the long-range ferromagnetic order.engjournal articlehttp://dx.doi.org/10.1103/PhysRevB.91.144418http://journals.aps.org/open access537Thin-filmsDomains.ElectricidadElectrónica (Física)2202.03 Electricidad