Regensburg 2010 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 28: Spin-dependent Transport Phenomena
MA 28.3: Vortrag
Donnerstag, 25. März 2010, 15:45–16:00, H3
Ab-initio transport calculations of Fe/MgO/Fe tunnel junctions modified by Co and Cr interlayers — •Peter Bose1,3, Jürgen Henk2, Peter Zahn1, and Ingrid Mertig1,2 — 1Martin Luther University Halle-Wittenberg, Germany — 2Max Planck Institute of Microstructure Physics, Halle, Germany — 3International Max Planck Research School for Science and Technology of Nanostructures
For spintronic device applications, large and tuneable tunnel magnetoresistance ratios (TMR) are inevitable. However, experimental TMR ratios of epitaxial Fe/MgO/Fe junctions can be strongly reduced by imperfect Fe/MgO interfaces. A way to increase the TMR ratio is the insertion of thin metallic layers at the Fe/MgO interfaces. With respect to their magnetic and electronic properties as well as their small lattice mismatch to Fe(001), Co and Cr interlayers have been preferably studied [1,2].
We report on systematic ab-initio investigations of Co and Cr interlayers focussing on the changes of the electronic structure and the transport properties. The results of spin-dependent ballistic transport calculations reveal options to specifically manipulate the TMR ratio. The observed effects are directly addressed and interpreted by means of electronic states with complex wave vectors.
[1] S. Yuasa et al., APL87 222508 (2005), [2] R. Matsumoto et al., PRB79 174436 (2009)