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TT: Fachverband Tiefe Temperaturen

TT 18: Spincaloric Transport
(Joint session of MA and TT organized by MA)

TT 18.6: Vortrag

Montag, 7. März 2016, 16:15–16:30, H31

Comparison of laser induced and intrinsic tunnel magneto-Seebeck effect in CoFeB/MgAl₂O₄/CoFeB magnetic tunnel junctions — •Torsten Huebner¹, Alexander Boehnke¹, Ulrike Martens², Markus Münzenberg², Andy Thomas³, Timo Kuschel¹, and Günter Reiss¹ — ¹CSMD, Physics Department, Bielefeld University, Germany — ²IFP, Greifswald University, Germany — ³IMW, IFW Dresden, Germany

The Seebeck coefficient of a Magnetic Tunnel Junction (MTJ) depends on its magnetic state known as the tunnel magneto-Seebeck (TMS) effect [1]. It has been extensively studied with indirect Joule and laser induced heating [2,3]. Zhang, Teixeira et al. [4,5] proposed a third method using the intrinsic Joule heating by the tunneling current without any external temperature gradient. Here, we prepared CoFeB/MgAl₂O₄/CoFeB MTJs and obtained a maximum tunnel magneto-resistance (TMR) ratio of 34 % at room temperature for a nominal barrier thickness of 1.8 nm. We used a modulated diode laser (P_max=150 mW, λ=637 nm, f=177 Hz) to generate a temperature gradient across the junctions and recorded IU-characteristics to compare the laser induced TMS with the intrinsic TMS.