2018/01/12 by Ulrike Martens, Torsten Huebner, Henning Ulrichs +8
Chemistry · Materials Science · Physics and Astronomy · #Advanced Physical and Chemical Molecular Interactions #Chemical and Physical Properties of Materials #Electrode #Ferromagnetism #Magnetic field #Magnetic flux #Magnetic properties of thin films #Magnetization #Nernst effect #Nernst equation #Temperature gradient #Temperature measurement #Thermomagnetic convection #cond-mat.mes-hall
paper · pdf · doi:10.1038/s42005-018-0063-y
published as Commun. Phys. 1, 65 (2018)
arxiv created 2018/01/12 · openalex created_date 2018/01/26 · openalex publication_date 2018/10/09 · arxiv updated 2018/10/18 · openalex updated_date 2026/08/05
Abstract Localized laser heating creates temperature gradients in all directions leading to three-dimensional electron flux in metallic materials. Temperature gradients in combination with material magnetization generate thermomagnetic voltages. The interplay between these temperature gradients and the magnetization along with their control enable to manipulate the generated voltages in magnetic nanodevices. We present a highly sensitive method to identify the anomalous Nernst effect generated on the nanometer length scale by micrometer-sized temperature gradients in magnetic tunnel junctions with CoFeB electrodes and a MgO tunnel barrier systematically extracted by analyzing the influence of in-plane temperature gradients on the tunnel magneto-Seebeck effect. This method yields an anomalous Nernst effect coefficient of K N ≈ 1.6 × 10 −8 V T −1 K −1 for CoFeB. Generally, such investigations are motivated by utilizing otherwise wasted heat in magnetic memory devices for read/write operations. The additionally generated anomalous Nernst effect offers a functionality expansion, opening new application fields such as direction-dependent temperature sensing with downscaling potential.