info:eu-repo/semantics/article
Interfacial effects on the tunneling magnetoresistance in La0.7Sr0.3MnO3/MgO/Fe tunneling junctions
Fecha
2015-09Registro en:
Galceran, R.; Balcells, Ll.; Martinez Boubeta, C.; Bozzo, B.; Cisneros Fernández, J.; et al.; Interfacial effects on the tunneling magnetoresistance in La0.7Sr0.3MnO3/MgO/Fe tunneling junctions; American Physical Society; Physical Review B: Condensed Matter and Materials Physics; 92; 9-2015; 94428-94428
1098-0121
CONICET Digital
CONICET
Autor
Galceran, R.
Balcells, Ll.
Martinez Boubeta, C.
Bozzo, B.
Cisneros Fernández, J.
de la Mata, Manuel
Magén, C.
Arbiol, J.
Tornos, J.
Cuellar, F. A.
Sefrioui, Z.
Cebollada, A.
Golmar, Federico
Hueso, Luis E.
Casanova, F.
Santamaría, J.
Martinez, B.
Resumen
We report on magnetotransport properties on La0.7Sr0.3MnO3/MgO/Fe tunnel junctions grown epitaxially on top of (001)-oriented SrTiO3 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 DELTA1 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.