%0 Journal Article
%A Mehta, V. V.
%A Biskup Zaja, Nevenko
%A Jenkins, C.
%A Arenholz, E.
%A Varela del Arco, María
%A Suzuki, Y.
%T Long-range ferromagnetic order in LaCoO3-delta epitaxial films due to the interplay of epitaxial strain and oxygen vacancy ordering
%D 2015
%@ 1098-0121
%U https://hdl.handle.net/20.500.14352/24036
%X 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.
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