Long-range ferromagnetic order in LaCoO3-delta epitaxial films due to the interplay of epitaxial strain and oxygen vacancy ordering
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_...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2015 |
| País: | España |
| Institución: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | inglés |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/24036 |
| Acceso en línea: | https://hdl.handle.net/20.500.14352/24036 |
| Access Level: | acceso abierto |
| Palabra clave: | 537 Thin-films Domains. Electricidad Electrónica (Física) 2202.03 Electricidad |
| Sumario: | 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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