First principles investigation of bulk skyrmion formation within the 50% Co-doped Fe5GeTe2 layered magnetic metal

The van der Waals-layered itinerant magnetic metal Fe5GeTe2 (F5GT) has recently garnered significant interest for its high-temperature and readily tunable magnetic ordering behavior. Moreover, the structural phase and interlayer stacking are highly sensitive to specific doping concentrations of Cobalt, leading to the formation of a polar structure at 50% doping that admits a zero-field neel-type skyrmion lattice at room temperature [1,2]. Here we perform ab-initio density functional theory calculations across a variety of structural instances of Co-doped F5GT to elucidate the relationship between atomic geometry, and compositional and magnetic order. These calculations provide new insight into how Co-substitution results in uncompensated in-plane Dzyaloshinskii-Moriya interactions that lead to skyrmion formation.