Interfacial electronic transport phenomena in single crystalline Fe-MgO-Fe thin barrier junctions

R. B. Gangineni (1, 2) , Christine Bellouard (3) , A. Duluard (3) , B. Negulescu (3, 4) , C. Baraduc (2) , G. Gaudin (2) , Coriolan Tiusan (5, 3)

1 Université de Pondichéry
2 SPINTEC - SPINtronique et TEchnologie des Composants
3 IJL - Institut Jean Lamour
4 GREMAN - UMR 7347 - GREMAN (matériaux, microélectronique, acoustique et nanotechnologies)
5 Technical University of Cluj-Napoca

Spin filtering effects in nano-pillars of Fe-MgO-Fe single crystalline magnetic tunnel junctions are explored with two different sample architectures and thin MgO barriers (thickness: 3-8 monolayers). The two architectures, with different growth and annealing conditions of the bottom electrode, allow tuning the quality of the bottom Fe/MgO interface. As a result, an interfacial resonance states (IRS) is observed or not depending on this interface quality. The IRS contribution, observed by spin polarized tunnel spectroscopy, is analyzed as a function of the MgO barrier thickness. Our experimental findings agree with theoretical predictions concerning the symmetry of the low energy (0.2 eV) interfacial resonance states: a mixture of Delta(1)-like and Delta(5)-like symmetries.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

R. B. Gangineni, Christine Bellouard, A. Duluard, B. Negulescu, C. Baraduc, et al.. Interfacial electronic transport phenomena in single crystalline Fe-MgO-Fe thin barrier junctions. Applied Physics Letters, 2014, 104 (18), ⟨10.1063/1.4875386⟩. ⟨hal-01282868⟩