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Tunnel magnetoresistance and robust room temperature exchange bias with multiferroic BiFeO3 epitaxial thin films

H. Bea·M. Bibes·S. Cherifi·F. Nolting·B. Warot-Fonrose·S. Fusil·G. Herranz·C. Deranlot·E. Jacquet·K. Bouzehouane·A. Barthelemy
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Abstract

We report on the functionalization of multiferroic BiFeO3 epitaxial films for spintronics. A first example is provided by the use of ultrathin layers of BiFeO3 as tunnel barriers in magnetic tunnel junctions with La2/3Sr1/3MnO3 and Co electrodes. In such structures, a positive tunnel magnetoresistance up to 30% is obtained at low temperature. A second example is the exploitation of the antiferromagnetic spin structure of a BiFeO3 film to induce a sizeable (~60 Oe) exchange bias on a ferromagnetic film of CoFeB, at room temperature. Remarkably, the exchange bias effect is robust upon magnetic field cycling, with no indications of training.

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H. Bea, M. Bibes, S. Cherifi, F. Nolting, B. Warot-Fonrose, S. Fusil, G. Herranz, C. Deranlot, E. Jacquet, K. Bouzehouane, A. Barthelemy. 2006-09-27. Tunnel magnetoresistance and robust room temperature exchange bias with multiferroic BiFeO3 epitaxial thin films. https://doi.org/10.1063/1.2402204

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