Magnetic domain walls of the van der Waals material Fe$_3$GeTe$_2$

TL;DR

This study combines experimental and theoretical methods to analyze magnetic domain walls in Fe$_3$GeTe$_2$, revealing the influence of electric fields and magnetic fields on its complex magnetic structures.

Contribution

It provides new insights into the microscopic domain wall profiles and the effects of electric and magnetic fields on Fe$_3$GeTe$_2$'s magnetism, using combined STM and spin-dynamics simulations.

Findings

Weak magneto-electric effect influences domain wall width.

Critical magnetic field for bubble domain collapse identified.

Microscopic domain wall profiles characterized.

Abstract

Among two-dimensional materials, Fe$_3$GeTe$_2$ has come to occupy a very important place owing to its ferromagnetic nature with one of the highest Curie temperatures among known van der Waals materials and the potential for hosting skyrmions. In this combined experimental and theoretical work, we investigate the magnetic bubble domains as well as the microscopic domain wall profile using spin-polarized scanning tunneling microscopy in combination with atomistic spin-dynamics simulations performed with parameters from density functional theory calculations. We find a weak magneto-electric effect influencing the domain wall width by the electric field in the tunneling junction and determine the critical magnetic field for the collapse of the bubble domains. Our findings shed light on the origins of complex magnetism that Fe$_3$GeTe$_2$ exhibits.