Large anomalous Nernst effect in thin films of the Weyl semimetal Co2MnGa

Reichlova H, Schlitz R, Beckert S, Swekis P, Markou A, Chen YC, Kriegner D, Fabretti S, Park GH, Niemann A, Sudheendra S, Thomas A, Nielsch K, Felser C, Goennenwein STB (2018)

Publication Type: Journal article

Publication year: 2018

Journal

Applied Physics Letters American Institute of Physics (AIP)

Book Volume: 113

Article Number: 212405

Journal Issue: 21

DOI: 10.1063/1.5048690

Abstract

The magneto-thermoelectric properties of Heusler compound thin films are very diverse. Here, we discuss the anomalous Nernst response of Co2MnGa thin films. We systematically study the anomalous Nernst coefficient as a function of temperature, and we show that unlike the anomalous Hall effect, the anomalous Nernst effect in Co2MnGa strongly varies with temperature. We exploit the on-chip thermometry technique to quantify the thermal gradient, which enables us to directly evaluate the anomalous Nernst coefficient. We compare these results to a reference CoFeB thin film. We show that the 50-nm-thick Co2MnGa films exhibit a large anomalous Nernst effect of -2 μV/K at 300 K, whereas the 10-nm-thick Co2MnGa film exhibits a significantly smaller anomalous Nernst coefficient despite having similar volume magnetizations. These findings suggest that the microscopic origin of the anomalous Nernst effect in Co2MnGa is complex and may contain contributions from skew-scattering, side-jump, or intrinsic Berry phase. In any case, the observed anomalous Nernst coefficient of -2 μV/K at 300 K is large compared to the values measured in other thin films and makes this material system a very promising candidate for efficient spin-caloritronic devices.

Involved external institutions

Technische Universität Dresden DE Germany (DE) Max-Planck-Institut für Chemische Physik fester Stoffe (MPI CPfS) / Max Planck Institute for Chemical Physics of Solids DE Germany (DE) Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden e.V. (IFW) / Leibniz Institute for Solid State and Materials Research Dresden DE Germany (DE)

How to cite

APA:

Reichlova, H., Schlitz, R., Beckert, S., Swekis, P., Markou, A., Chen, Y.-C.,... Goennenwein, S.T.B. (2018). Large anomalous Nernst effect in thin films of the Weyl semimetal Co2MnGa. Applied Physics Letters, 113(21). https://doi.org/10.1063/1.5048690

MLA:

Reichlova, Helena, et al. "Large anomalous Nernst effect in thin films of the Weyl semimetal Co2MnGa." Applied Physics Letters 113.21 (2018).

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