Authors
Alan Kalitsov, Pierre-Jean Zermatten, Frédéric Bonell, Gilles Gaudin, Stéphane Andrieu, Coriolan Tiusan, Mairbek Chshiev, Julian P Velev
Publication date
2013/11/6
Journal
Journal of Physics: Condensed Matter
Volume
25
Issue
49
Pages
496005
Publisher
IOP Publishing
Description
The transport properties of magnetic tunnel junctions (MTJs) are very sensitive to interface modifications. In this work we investigate both experimentally and theoretically the effect of asymmetric barrier modifications on the bias dependence of tunneling magnetoresistance (TMR) in single crystal Fe/MgO-based MTJs with (i) one crystalline and one rough interface, and (ii) with a monolayer of O deposited at the crystalline interface. In both cases we observe an asymmetric bias dependence of TMR and a reversal of its sign at large bias. We propose a general model to explain the bias dependence in these and similar systems reported earlier. The model predicts the existence of two distinct TMR regimes:(i) a tunneling regime when the interface is modified with layers of a different insulator, and (ii) a resonant regime when thin metallic layers are inserted at the interface. We demonstrate that in the tunneling regime …
Scholar articles
Bias dependence of tunneling magnetoresistance in magnetic tunnel junctions with asymmetric barriers
A Kalitsov, PJ Zermatten, F Bonell, G Gaudin… - Journal of Physics: Condensed Matter, 2013