Hard magnetic properties in nanoflake van der Waals Fe3GeTe2

TL;DR

This study investigates the magnetic properties of nanoflake Fe3GeTe2, revealing strong perpendicular magnetic anisotropy, high coercivity, and interlayer magnetic coupling, which are promising for spintronic applications.

Contribution

It provides detailed characterization of the thickness-dependent magnetic properties of vdW Fe3GeTe2, including a new model explaining its hard magnetic behavior.

Findings

Nanoflakes exhibit a single hard magnetic phase with large coercivity.

Magnetic coupling exists between vdW layers with an estimated length of ~5 layers.

The magnetic behavior is well described by a proposed theoretical model.

Abstract

Two dimensional (2D) van der Waals (vdW) materials have demonstrated fascinating optical, electrical and thickness-dependent characteristics. These have been explored by numerous authors but reports on magnetic properties and spintronic applications of 2D vdW materials are scarce by comparison. By performing anomalous Hall effect transport measurements, we have characterised the thickness dependent magnetic properties of single crystalline vdW Fe3GeTe2. The nanoflakes of this vdW metallic material exhibit a single hard magnetic phase with a near square-shaped magnetic loop, large coercivity (up to 550 mT at 2 K), a Curie temperature near 200 K and strong perpendicular magnetic anisotropy. Using criticality analysis, we confirmed the existence of magnetic coupling between vdW atomic layers and obtained an estimated coupling length of ~ 5 vdW layers in Fe3GeTe2. Furthermore, the hard magnetic behaviour of Fe3GeTe2 can be well described by a proposed model. The magnetic properties of Fe3GeTe2 highlight its potential for integration into vdW magnetic heterostructures, paving the way for spintronic research and applications based on these devices.