Extended Data Figure 9: Crystal structure consisting of magnetic ion Cr only.
From: Discovery of intrinsic ferromagnetism in two-dimensional van der Waals crystals
Illustration of in-plane (left) and out-of-plane (right) nearest-neighbour exchange interactions. The ABC-type stacked hexagonal lattice is a reduced illustration of atomic arrangement of Cr in bulk Cr2Ge2Te6 crystals. J1, J2 and J3 (Jz1, Jz2 and Jz3) represent the first, second and third in-plane (out-of-plane) nearest-neighbour spin–spin exchange interactions, respectively. Positive and negative J values represent antiferromagnetic and ferromagnetic exchange interactions. Each Cr site carries a spin S = 3/2 in theoretical simulations. Blue and orange circles represent the Cr ions on A and B sublattices, respectively.
