Ab initio study of exchange interactions in the magnetic systems based on Cr2Ge2 X6 (X=S, Se, Te)

Abstract

Limiting the dimension of the spin sublattice (atoms with a magnetic moment) leads in most cases to the destruction of the long-range magnetic order. However, layered van der Waals structures (vdW materials) appear low-dimensional magnetism. Recently, the first 2D magnet based on an intrinsic vdW Ising compound (FePS 3 ) was exfoliated from crystals with 3D magnetic order. 2D vdW monolayers are a promising class of materials as a functional layer in spintronic devices. Magnetic exchange energy plays a key role in the formation of magnetic order. This type of energy is determined by the integral of the exchange interaction, which characterizes the degree of the electrons wave functions overlap (or atomic orbitals). The exchange interaction integral is calculated using ab initio simulation and the Heisenberg model. The values of the exchange interaction integral can help to establish the ground magnetic order. The article presents the results of the exchange interaction integrals calculations for Cr2Ge2 X6 (X=S, Se, Te) compounds.