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MA: Fachverband Magnetismus

MA 61: Caloric Effects

MA 61.2: Vortrag

Freitag, 20. März 2020, 09:45–10:00, HSZ 101

Magnetocaloric materials for multi-stimuli cooling cycle - required functional properties and potential materials — •Franziska Scheibel¹, Tino Gottschall², Lukas Pfeuffer¹, Andreas Taubel¹, Dominik Ohmer¹, Konstantin Skokov¹, Bai-Xiang Xu¹, and Oliver Gutfleisch¹ — ¹Technische Universität Darmstadt, Darmstadt, Germany — ²Dresden High Magnetic Field Laboratory (HLD-EMFL), HZDR, Germany

Materials with a first-order magnetostructural phase transition (FOMST) exhibit a large magnetocaloric effect. However, due to the thermal hysteresis coming along with FOMST the cyclic performance of that materials is limited. The origins of the hysteresis are quite complex but this complexity can also be utilized to tune it [1,2]. So far, a lot of research has been directed towards reducing the hysteresis. Our new cooling concept actually attempts to exploit hysteresis in a multi-stimuli approach [3]. Herein, a second stimulus (uniaxial load) besides the magnetic field stimulus is used to overcome hysteresis and enable a fully reversible FOMST and therefore increase the cyclic performance of the magnetocaloric material. For the multi-stimuli approach a variety of new functional properties are required and we present here a first summary of experimental and theoretical findings on tailored Ni-Mn-X Heusler alloys as potential candidates. This work was supported by the ERC Advanced Grant "Cool Innov" and the SFB-TRR270 "Hommage". [1] O. Gutfleisch et al., Phil. Trans. R. Soc. A 374: 20150308 (2016) [2] F. Scheibel et al., Energy Technol. 6, 1397 (2018) [3] T. Gottschall et al., Nat. Mater. 17, 929 (2018)