Regensburg 2022 – wissenschaftliches Programm

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KFM: Fachverband Kristalline Festkörper und deren Mikrostruktur

KFM 29: Multiferroics and Magnetoelectric Coupling (joint session MA/KFM)

KFM 29.4: Vortrag

Donnerstag, 8. September 2022, 15:45–16:00, H47

Magnetization reversal through an antiferromagnetic state — •Somnath Ghara¹, Evgenii Barts², Kirill Vasin¹, Dmytro Kamenskyi¹, Lilian Prodan¹, Vladimir Tsurkan¹, Maxim Mostovoy², Istvan Kezsmarki¹, and Joachim Deisenhofer¹ — ¹Experimentalphysik V, University of Augsburg, Augsburg, Germany — ²University of Groningen, Groningen, The Netherlands

The polar magnet Fe₂Mo₃O₈ has recently attracted tremendous interests due its versatile properties, such as magnetoelectric effect and giant thermal hall effect. This compound has a polar hexagonal (space group P6₃mc) structure at room temperature and undergoes a collinear antiferromagnetic ordering of Fe²⁺ moments below T_N = 60 K, accompanied by a large electric polarization besides that of the structural origin. Upon application of (high) magnetic field, a metamagnetic transition from the antiferromagnetic to a ferrimagnetic state takes place. The ferrimagnetic state can also be stabilized by partially substituting Fe²⁺ ions by Zn²⁺ ions. The magnetic symmetry (6m^′m^′) of the ferrimagnetic state is compatible with a linear magnetoelectric effect. In this talk, I will show that at the coercive field of the isothermal reversal of a ferrimagnetic state in Fe_1.86Zn_0.14Mo₃O₈ the pristine antiferromagnetic state re-emerges as a metastable state. The reappearance of the antiferromagnetic state, supported by the theoretical calculations, is reflected in a large change of electric polarization and directly established by the reoccurrence of the characteristic low-energy THz excitation of the AFM state.