Regensburg 2019 – wissenschaftliches Programm
MA 12.3: Vortrag
Montag, 1. April 2019, 17:45–18:00, H53
Anomalous Nernst effect in magnetic tunnel junctions: A concept for direction dependent temperature sensing — Ulrike Martens1, Torsten Huebner2, Henning Ulrichs3, Oliver Reimer2, Timo Kuschel2, Ronnie Tamming4, Chia-Lin Chang4, Raanan Tobey4, Andy Thomas5, Markus Münzenberg1, and •Jakob Walowski1 — 1Universität Greifswald, Greifswald, Germany — 2Bielefeld University, Bielefeld, Germany — 3Universität Göttingen, Göttingen, Germany — 4University of Groningen, Groningen, The Netherlands — 5IFW Dresden, Institute for Metallic Materials, Dresden, Germany
CoFeB/MgO based magnetic tunnel junctions (MTJs) exhibit a large tunnel magnetoresistence effect due to a high spin polarization given by the material combination. This enables information storage based on the magnetization state. Replacing the voltage as a driving force for the spin polarized currents by temperature gradients opens up new functionalities for these devices. By applying a homogeneous temperature gradient across the tunnel barrier, the tunneling magneto-Seebeck effect (TMS) can be used as a readout method, because the generated voltage is magnetization dependent. Inhomogeneous temperature gradients generate additional thermomagnetic effects, which have an impact on the TMS. Those effects, e.g. the anomalous Nernst effect (ANE), can be extracted by systematically changing the temperature gradient direction and measuring the TMS. We demonstrate, that analyzing the ANE with respect to the temperature gradient directions, allows for direction dependent temperature sensing.