Large reduction of the magnetoresistance in Fe/MgO/Fe tunnel junctions due to small oxygen concentrations at a single FeO interface layer: A first-principles study

被引：29
作者：
Bose, P. [1 ]
Ernst, A. [2 ]
Mertig, I. [1 ]
Henk, J. [2 ]
机构：
[1] Univ Halle Wittenberg, D-06099 Halle, Saale, Germany
[2] Max Planck Inst Mikrostrukturphys, D-06120 Halle, Saale, Germany
来源：
PHYSICAL REVIEW B | 2008年 / 78卷 / 09期
关键词：
D O I：
10.1103/PhysRevB.78.092403
中图分类号：
T [工业技术];
学科分类号：
08 ;
摘要：
The tunneling magnetoresistance (TMR) of Fe/MgO/Fe junctions is strongly diminished by small O concentrations in a single partially oxidized FeO interface layer, as is found by first-principles transport calculations. By modeling the electronic transport through the disordered FeO layer within a supercell approach, the effect is traced back to a significant reduction of specular contributions to the conductances of the parallel configuration of the lead magnetizations. These findings bring theoretical TMR ratios closer to their experimental counterparts and highlight the importance of ordered interfaces for large TMR ratios.
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