Magnetization reversal through an antiferromagnetic state

Abstract

Magnetization reversal in ferro- and ferrimagnets is a well-known archetype of non-equilibrium processes, where the volume fractions of the oppositely magnetized domains vary and perfectly compensate each other at the coercive magnetic field. Here, we report on a fundamentally new pathway for magnetization reversal that is mediated by an antiferromagnetic state. Consequently, an atomic-scale compensation of the magnetization is realized at the coercive field, instead of the mesoscopic or macroscopic domain cancellation in canonical reversal processes. We demonstrate this unusual magnetization reversal on the Zn-doped polar magnet Fe${}_2$Mo${}_3$O${}_8$. Hidden behind the conventional ferrimagnetic hysteresis loop, the surprising emergence of the antiferromagnetic phase at the coercive fields is disclosed by a sharp peak in the field-dependence of the electric polarization. In addition, at the magnetization reversal our THz spectroscopy studies reveal the reappearance of the magnon mode that is only present in the pristine antiferromagnetic state. According to our microscopic calculations, this unusual process is governed by the dominant intralayer coupling, strong easy-axis anisotropy and spin fluctuations, which result in a complex interplay between the ferrimagnetic and antiferromagnetic phases. Such antiferro-state-mediated reversal processes offer novel concepts for magnetization control, and may also emerge for other ferroic orders.

arXiv comment8 pages, 4 figures

References in corpus (13)

• Unveiling hidden ferrimagnetism and giant magnetoelectricity in polar magnet Fe2Mo3O8
• Electrical control of large magnetization reversal in a helimagnet
• Thermal Hall effect, spin Nernst effect, and spin density induced by thermal gradient in collinear ferrimagnets from magnon-phonon interaction
• High-temperature terahertz optical diode effect without magnetic order in polar FeZnMo${}_3$O${}_8$
• FeCr${}_2$S${}_4$ in magnetic fields: possible evidence for a multiferroic ground state
• Electromagnon resonance in a collinear spin state of a polar antiferromagnet Fe2Mo3O8
• Microscopic toy model for magnetoelectric effect in polar Fe${}_2$Mo${}_3$O${}_8$
• Interconversion of multiferroic domains and domain walls
• Picosecond creation of switchable optomagnets with giant photoinduced Kerr rotations in polar antiferromagnetic (Fe${}_{1-x}$Zn${}_x$)${}_2$Mo${}_3$O${}_8$
• Magnetic and vibronic THz excitations in Zn doped Fe${}_2$Mo${}_3$O${}_8$
• Ordering of Fe and Zn ions and magnetic properties of FeZnMo3O8
• Diffusive Excitonic Bands from Frustrated Triangular Sublattice in a Singlet-Ground-State System
• Resolving structural changes and symmetry lowering in spinel FeCr2S4

Cited by in corpus (3)

• Optical magnetoelectric effect in the polar honeycomb antiferromagnet Fe2Mo3O8
• More bridging ligands activate direct exchange: the case of anisotropic Kitaev effective magnetic interactions
• Optical phonons as a testing ground for spin group symmetries