Fig. 1: Crystal structure of FenGeTe2 monolayers.

Side views of a Fe3GeTe2, b Fe4GeTe2, c UUU Fe5GeTe2, and d UDU Fe5GeTe2 are side views of monolayers, where orange, yellow, and blue circles represent Fe, Te, and Ge atoms, respectively. Direction of the arrows shown inside Fe atoms, indicates the easy axis of magnetization obtained from our DFT + DMFT calculations. The half-colored circles in Fig. 1d show the Fe1-Ge split sites present in the UDU configuration. The green arrow drawn in each system shows the pair of Fe atoms exhibiting the strongest isotropic symmetric exchange interaction between each other. The lower panel shows 3D side view of FenGeTe2 monolayers.