Berlin 2012 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 42: Joint Session "Novel Spincaloritronic Devices: Control of Heat, Charge and Momentum Flow" (jointly with TT), Organization: Markus Münzenberg (Univ. Göttingen), Mathias Weiler (WMI Garching)

MA 42.2: Topical Talk

Donnerstag, 29. März 2012, 15:30–16:00, EB 301

Magneto Seebeck effect in tunnel junctions — •Christian Heiliger — I. Physikalisches Institut, Justus Liebig University Giessen

The magneto Seebeck effect in magnetic tunnel junctions is the change of the Seebeck coefficient or thermopower caused by switching the relative magnetic orientation of the two ferromagnetic leads. For MgO based tunnel junctions we predict by ab initio calculations that the magneto Seebeck ratio can exceed several 1000% and depends strongly on temperature [1]. I will discuss the role of different magnetic materials and show the importance of the termination of the magnetic layer next to the MgO barrier for ordered FeCo alloys. In particular, the size of the magneto Seebeck ratio can change by two orders of magnitude and even the sign can be changed by changing the termination of the magnetic layer [2]. Further, I analyze the influence of the barrier thickness on the magneto Seebeck ratio. The theoretical results will be compared to recent experimental results [2].

[1] M. Czerner, M. Bachmann, C. Heiliger, Phys. Rev. B 83, 132405 (2011) [2] M. Walter, J. Walowski, V. Zbarsky, M. Münzenberg, M. Schäfers, D. Ebke, G. Reiss, A. Thomas, P. Peretzki, M. Seibt, J. S. Moodera, M. Czerner, M. Bachmann, C. Heiliger, Nature Materials 10, 742 (2011)