Berlin 2024 – scientific programme
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MA: Fachverband Magnetismus
MA 51: Caloric Effects in Ferromagnetic Materials
MA 51.4: Talk
Friday, March 22, 2024, 10:30–10:45, H 2013
Measuring the Anomalous Ettingshausen effect in the magnetic Weyl semimetal Co2MnGa — •Mohammadali Razeghi and Pascal Gehring — IMCN/NAPS, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
Magnetic Weyl semimetals (MWSMs) have been praised for their exceptional electrical transport properties. Often overlooked, energy and heat transport properties remain to be investigated. Especially coupled properties, such as heat to charge conversion, are expected to be enhanced by topological effects in MWSMs. The Heusler alloy Co2MnGa has been reported to show MWSM state at room temperature with large anomalous Hall and Nernst coefficients.
In this work, we explore the cooling capability of Co2MnGa devices using Scanning Thermal Microscopy (SThM). SThM allows us to locally map temperature variations and to trigger temperature driven electrical transport effects in micropatterned Co2MnGa devices. We explore thermomagnetic and thermoelectric effects and their interplay with geometry, charge density and magnetic field. In particular we observe a pronounced anomalous Ettingshausen effect and reveal a strong contribution from band topology to its magnitude. We furthermore quantify the cooling and heating efficiency of the topological alloy and assess its potential for realization of heat management devices.
Keywords: Magnetic Weyl semimetal; Ettingshausen effect; Scanning thermal microscopy; Cooling devices