Dresden 2014 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 85: Spincaloric Transport II (organized by MA)

TT 85.1: Talk

Thursday, April 3, 2014, 09:30–09:45, HSZ 04

6000 % tunnel magneto-Seebeck effect under applied bias — •Alexander Boehnke¹, Marius Minikel², Marvin Walter², Vladylsav Zbarsky², Karsten Rott¹, Andy Thomas¹, Markus Münzenberg², and Günter Reiss¹ — ¹Thin Films and Physics of Nanostructures, Bielefeld University, Germany — ²I. Physikalisches Institut, Georg-August-Universität Göttingen, Germany

Recently, significantly different values of the tunnel magneto-Seebeck effect (TMS) [1-5] have been reported when the material system of the magnetic tunnel junction (MTJ) is changed. Ab initio calculations shine first light on the origin of these differences, as they propose a strong influence of the lead material on the TMS [6]. We applied an additional bias voltage V_Bias to MTJs while measuring the TMS.

This well-defined tuning of the electrodes’ Fermi level positions allows to compare the bias voltage dependence of the TMS with the theoretical predictions. We demonstrate drastically changing TMS ratios of up to 6000 % generated by the variation of the bias voltage. At certain values of V_Bias, an on/off behavior of the Seebeck voltage is found when the magnetization alignment of an MTJ is reversed. These findings are in good agreement with the ab into calculations [6].

[1] M. Walter et al. (2011). Nat. Mater., 10(10), 742.

[2] N. Liebing et al. (2011). Phys. Rev. Lett., 107(17), 177201.

[3] W. Lin et al. (2012). Nat. Commun., 3, 744.

[4] N. Liebing et al. (2013). Appl. Phys. Lett., 102(24), 242413.

[5] A. Boehnke et al. (2013). Rev. Sci. Instrum., 84(6), 063905.

[6] C. Heiliger et al. (2013). Phys. Rev. B, 87(22), 224412.