Magnetic phases and zone-folded phonons in a frustrated van der Waals magnet

TL;DR

This paper investigates the magnetic phases of the frustrated van der Waals magnet CrOCl, revealing complex magnetic field-induced phases and associated zone-folded phonons, thus expanding understanding of 2D magnetic materials.

Contribution

It establishes the magnetic phase diagram of CrOCl using experimental and theoretical methods, highlighting the role of magnetic frustration and zone-folded phonons in such systems.

Findings

Identification of magnetic field-induced phases in CrOCl

Observation of zone-folded phonons related to magnetic superstructures

Theoretical insights into exchange interactions and lattice vibrations

Abstract

2D magnetic materials have attracted extensive research interest due to their potential application in nanospintronics, optospintronics, and in magnonics. Ferromagnetic as well as antiferromagnetic layered materials have been demonstrated and successfully inserted into van der Waals heterostructures. However, the effects of magnetic frustration in van der Waals materials and the possibilities offered by spin configurations characterized by nonlinear spin arrangements have not been fully considered yet. Herein, we establish the magnetic phase diagram of bulk CrOCl, a frustrated van der Waals magnet, using magnetization and magneto-optical spectroscopy techniques. In particular, we use the magnetic superstructures relative to the crystallographic unit cell and the associated rich zone-folded phonon series to describe the magnetic field induced phases. Theoretical calculations taking into account the competing nearest neighbors magnetic exchange interactions provide a unique insight into the lattice vibrations of this class of magnetic system. This study expands the scope of 2D magnetic materials and provides a methodology to characterize frustrated van der Waals magnets.