Dresden 2014 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MA: Fachverband Magnetismus
MA 55: Poster II
MA 55.19: Poster
Freitag, 4. April 2014, 10:30–13:30, P2
Ab initio investigation of the tunneling magneto Seebeck effect — •Christian Franz, Michael Czerner, and Christian Heiliger — I. Physikalisches Institut, Justus Liebig University, Giessen, Germany
The Seebeck coefficient describes the thermoelectric voltage induced in a junction by a temperature gradient. In a magnetic tunnel junction the Seebeck coefficient depends on the relative orientation of the magnetizations. This is termed tunneling magneto-Seebeck effect (TMS) or magneto-thermoelectric power. It is defined in analogy to the tunnel magnetoresistance and belongs to the research field of spin caloritronics. The TMS has been predicted theoretically [1] and confirmed experimentally [2].
In this contribution we show ab initio results for the TMS in FexCo1−x/MgO/FexCo1−x tunnel junctions [3]. We use a non-equilibrium Green’s function method for the transport properties and the coherent potential approximation with vertex corrections to describe the alloys [4]. We investigate the TMS for varying alloy composition, barrier thickness, and temperature. We find that the TMS depends sensitively on the parameters, in particular the alloy composition. This behavior can be traced back to the respective dependence of the transmission function.
[1] M. Czerner et. al, Phys. Rev. B 83, 132405 (2011)
[2] M. Walter et. al, Nat. Mater. 10, 742 (2011)
[3] C. Franz et. al, Phys. Rev. B 88, 094421 (2013)
[4] C. Franz et. al, J. Phys.: Condens. Matter 25, 425301 (2013)