Regensburg 2013 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 20: Transport: Spincaloric Transport (jointly with MA)

TT 20.7: Talk

Monday, March 11, 2013, 16:30–16:45, H22

Laser induced magneto-Seebeck effect on different substrate materials — •Alexander Böhnke¹, Marvin Walter², Karsten Rott¹, Andy Thomas¹, Markus Münzenberg², and Günter Reiss¹ — ¹Thin Films and Physics of Nanostructures, Bielefeld University, Germany — ²I. Physikalische Institut, Georg-August-Universität Göttingen, Germany

Since the discovery of the magneto-Seebeck effect [1,2,3] (TMS, tunnel magneto-Seebeck) a proper interpretation of the time-resolved voltage traces has been missing [1]. Improvements in the time resolution of the TMS setup now give access to the investigation of the origin of the Seebeck voltage.

Further, we investigated magnetic tunnel junctions (MTJs) on two different substrate materials: Insulating MgO and semiconducting p-doped Si covered by 50 nm of SiO₂. TMS measurements on both sample types lead to same results. However, the time-resolved voltage traces in the case of silicon substrate showed a sharp peak when the laser is turned on. On MgO substrate this peak is not found. SPICE simulations of comparable MTJs on both substrates were performed and can give a first glance on thermal voltages occurring in the layer stacks and the substrates due to laser heating and capacitive coupling.

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

[2] C. Heiliger et al., Phys. Rev. B 83 (2011), 1.

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