Influence of a Ta spacer on the magnetic and transport properties of perpendicular magnetic tunnel junctions

Léa Cuchet (1) , Bernard Rodmacq (1) , Stéphane Auffret (1) , Ricardo C. Sousa (1) , Clarisse Ducruet (1) , Bernard Dieny (1)

1 SPINTEC - SPINtronique et TEchnologie des Composants

Ultrathin Ta layers were inserted in the bottom hard (Co/Pt)/Ta/CoFeB/MgO magnetic electrode of perpendicular magnetic tunnel junctions. The magnetization of the top part of this electrode abruptly falls in-plane when the Ta thickness exceeds 0.45 nm. This results from the balance between the various energy terms acting on this layer (exchange-like coupling through Ta, demagnetizing energy, and perpendicular anisotropy at the CoFeB/MgO interface). For small Ta thicknesses, this insertion leads to a strong improvement of the tunnel magnetoresistance, as long as the magnetization of all layers remains perpendicular-to-plane.

Domains: Physics [physics]

Léa Cuchet, Bernard Rodmacq, Stéphane Auffret, Ricardo C. Sousa, Clarisse Ducruet, et al.. Influence of a Ta spacer on the magnetic and transport properties of perpendicular magnetic tunnel junctions. Applied Physics Letters, 2013, 103 (5), pp.052402. ⟨10.1063/1.4816968⟩. ⟨cea-01073021⟩