Interfacial effects on the tunneling magnetoresistance in La0.7 S r0.3Mn O3/MgO/Fe tunneling junctions

Galceran, R. ; Balcells, L. ; Martinez-Boubeta, C. ; Bozzo, B. ; Cisneros-Fernández, J. ; Mata, De La ; Magén, C. (Universidad de Zaragoza) ; Arbiol, J. ; Tornos, J. ; Cuellar, F.A. ; Sefrioui, Z. ; Cebollada, A. ; Golmar, F. ; Hueso, L.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 ¿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~120K) 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.

Idioma: Inglés

DOI: 10.1103/PhysRevB.92.094428

Año: 2015

Publicado en: Physical Review B 92, 9 (2015), 094428 [7 pp]
ISSN: 1098-0121

Factor impacto JCR: 3.718 (2015)

Categ. JCR: PHYSICS, CONDENSED MATTER rank: 16 / 67 = 0.239 (2015) - Q1 - T1

Factor impacto SCIMAGO: 2.377 - Electronic, Optical and Magnetic Materials (Q1) - Condensed Matter Physics (Q1)

Financiación: info:eu-repo/grantAgreement/EC/FP7/256470/EU/Injection, transport and manipulation of spin currents in new organic materials/ITAMOSCINOM
Financiación: info:eu-repo/grantAgreement/ES/MINECO/Consolider-Ingenio2010-CSD2009-00013
Financiación: info:eu-repo/grantAgreement/ES/MINECO/MAT2011-27470-C02
Financiación: info:eu-repo/grantAgreement/ES/MINECO/MAT2012-33207
Financiación: info:eu-repo/grantAgreement/ES/MINECO/MAT2012-37638

Tipo y forma: Artículo (Versión definitiva)

Área (Departamento): Área Física Materia Condensada (Dpto. Física Materia Condensa.)