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Observation of band structure and density of states effects in Co-based magnetic tunnel junctions

P. LeClair·J. T. Kohlhepp·C. H. van de Vin·H. Wieldraaijer·H. J. M. Swagten·W. J. M. de Jonge·A. H. Davis·J. M. MacLaren·R. Jansen·J. S. Moodera
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Abstract

Utilizing Co/Al$_2$O$_3$/Co magnetic tunnel junctions (MTJs) with Co electrodes of different crystalline phases, a clear relationship between electrode structure and junction transport properties is presented. For junctions with one fcc(111) textured and one polycrystalline (poly-phase and poly-directional) Co electrode, a strong asymmetry is observed in the magnetotransport properties, while when both electrodes are polycrystalline the magnetotransport is essentially symmetric. These observations are successfully explained within a model based on ballistic tunneling between the calculated band structures (DOS) of fcc-Co and hcp-Co.

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P. LeClair, J. T. Kohlhepp, C. H. van de Vin, H. Wieldraaijer, H. J. M. Swagten, W. J. M. de Jonge, A. H. Davis, J. M. MacLaren, R. Jansen, J. S. Moodera. 2001-07-27. Observation of band structure and density of states effects in Co-based magnetic tunnel junctions. https://doi.org/10.1103/physrevlett.88.107201

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