2026-06-27T15:56:45Zhttps://docta.ucm.es/rest/oai/request

oai:docta.ucm.es:20.500.14352/242172024-03-08T16:14:26Zcom_20.500.14352_14col_20.500.14352_15

Galceran, R. Balcells, Ll. Martínez-Boubeta, C. Bozzo, B. Cisneros-Fernández, J. Mata, M. de la Magén, C. Arbiol, J. Tornos, J. Cuéllar Jiménez, Fabian Andrés Sefrioui, Zouhair Cebollada, A. Golmar, F. Huesos, L.E. Casanova, F. Santamaría Sánchez-Barriga, Jacobo Martínez, B. 2023-06-18T06:47:51Z 2023-06-18T06:47:51Z 2015-09-16 1098-0121 10.1103/PhysRevB.92.094428 https://hdl.handle.net/20.500.14352/24217 http://dx.doi.org/10.1103/PhysRevB.92.094428 http://journals.aps.org/ We report on magnetotransport properties on La_(0.7)Sr_(0.3)MnO_(3)/MgO/Fe tunnel junctions grown epitaxially on top of (001)-oriented SrTiO_(3) substrates by sputtering. It is shown that the magnetoresistive response depends critically on the MgO/Fe interfacial properties. The appearance of an FeOX layer by the interface destroys the 1 symmetry filtering effect of the MgO/Fe system and only a small negative tunneling magnetoresistance (TMR) (∼ −3 %) is measured. However, in annealed samples a switchover from positive TMR (∼ +25% at 70 K) to negative TMR (∼ −1 %) is observed around 120 K. This change is associated with the transition from semiconducting at high T to insulating at low T taking place at the Verwey transition (TV ∼ 120 K) in Fe3O4, thus suggesting the formation of a very thin slab of magnetite at the MgO/Fe interface during annealing treatments. These results highlight the relevance of interfacial properties on the tunneling conduction process and how it can be substantially modified through appropriate interface engineering. eng open access Interfacial effects on the tunneling magnetoresistance in La_(0.7)Sr_(0.3)MnO_(3)/MgO/Fe tunneling junctions journal article