We study the electronic and magnetic properties of monolayer ${\mathrm{Fe}}_3{\mathrm{GeTe}}_2$ within the density-functional plus dynamical mean-field theory approach in the paramagnetic phase. We argue that this compound is sufficiently far from the local magnetic moment limit, demonstrating nonlinear temperature dependencies of the partial inverse local and uniform magnetic susceptibilities in a broad temperature range. We find that in the regime of moderate Coulomb interactions ($U=3–4\mathrm{eV}$), the iron atoms located above and below the Ge plane carry a substantial local magnetic moment ($\mu \gtrsim 4.5{\mu }_B$), while the iron atom located within the Ge plane does not exhibit any pronounced magnetic moment. At the same time, the exchange interaction between these two symmetry-nonequivalent types of atoms turns out to be crucial for stabilizing long-range ferromagnetic order in ${\mathrm{Fe}}_3{\mathrm{GeTe}}_2$. The estimated spin-wave stiffness and Curie temperature are in good agreement with the experimental data, indicating that a dynamical treatment of electron correlations in ${\mathrm{Fe}}_3{\mathrm{GeTe}}_2$ is essential to properly describe its partially itinerant magnetic behavior.

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• Exchange interaction
• Magnetism
• RKKY interaction
• Ferromagnets
• Two-dimensional electron system
• Magnetic moment
• Dynamical mean field theory