For the van der Waals magnet ${\mathrm{Fe}}_3{\mathrm{GeTe}}_2$, although a ferromagnetic ground state has been reported, there are also reports of complex magnetic behavior suggesting coexistence of ferromagnetism and antiferromagnetism due to the intricate interaction between ${\mathrm{Fe}}^{+3}$ and ${\mathrm{Fe}}^{+2}$ ions in this system. The exact nature of the interactions and the origin of antiferromagnetism are still under debate. Here, we report a clear signature of intrinsic intralayer antiferromagnetic coupling coexisting with ferromagnetic couplings between different Fe ions in the anomalous Hall effect measured for devices of mechanically exfoliated ${\mathrm{Fe}}_3{\mathrm{GeTe}}_2$ nanoflakes of thicknesses of $\sim 20\mathrm{nm}$. Two sharp steplike jumps in the hysteresis loop of anomalous Hall resistance ($R_{\mathrm{xy}}$) measured as a function of external field $\left(H\right)$ at temperatures below the onset temperature of antiferromagnetic coupling. Our detailed analysis of experimental data suggests the jumps in $R_{\mathrm{xy}}\left(H\right)$ correspond to magnetization switching behavior of different Fe ions in individual layers of ${\mathrm{Fe}}_3{\mathrm{GeTe}}_2$. The experimental results are supported by first-principles calculations, suggesting a coexisting intralayer antiferromagnetic coupling between ${\mathrm{Fe}}^{+3}$ and ${\mathrm{Fe}}^{+3}$ ions and ferromagnetic coupling between ${\mathrm{Fe}}^{+3}$ and ${\mathrm{Fe}}^{+2}$ ions in the system.

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• Electrical properties
• Hall effect
• Magnetic interactions
• Magnetism
• Magnetotransport
• 2-dimensional systems
• Antiferromagnets
• Device fabrication
• Devices
• Ferromagnets
• Magnetic systems
• Transition metal dichalcogenides
• van der Waals systems
• First-principles calculations
• Magnetization measurements