Layer-Dependent Magnetic Domains in Atomically Thin Fe₅GeTe₂

Area of Science:

• Condensed Matter Physics
• Materials Science

Background:

• Magnetic domain formation in 2D materials is crucial for understanding 2D magnetism and developing spintronics.
• Characterizing magnetic domains in atomically thin van der Waals (vdW) flakes presents significant challenges.

Purpose of the Study:

• To investigate the layer-resolved magnetic domain structures in the itinerant vdW ferromagnet Fe5GeTe2.
• To understand the influence of flake thickness on magnetic domain behavior and spin orientation.

Main Methods:

• Utilized X-ray photoemission electron microscopy (XPEEM) for high-resolution imaging.
• Performed layer-resolved analysis of domain structures in Fe5GeTe2 flakes of varying thicknesses.

Main Results:

• Observed labyrinth-type domains in bulk Fe5GeTe2, transitioning to fragmented domains in thinner flakes.
• Identified a spin-reorientation transition where spins cant in-plane for flakes thinner than six layers.
• Discovered a bubble phase in four-layer Fe5GeTe2 flakes, deviating from typical 2D magnetic material behavior.

Conclusions:

• The thickness-dependent magnetic domain evolution in Fe5GeTe2 deviates from single-domain behavior seen in other 2D magnets.
• Complex spin textures can be stabilized in 2D vdW magnets at relatively high temperatures.
• Fe5GeTe2 offers exciting prospects for advanced spintronics applications due to its tunable magnetic properties.