Functionalization of low-dimensional honeycomb germanium with 3d transition-metal atoms

The semi-metal 2D Ge can change to either FM or AFM metals after 3d TM adsorption. TM atom at edge hexagon hollow site yields the minimum energy state. 3d TM-adsorbed AGeNRs can be either metals or semiconductors with FM or AFM alignment. The Cr and Mn adsorptions make certain AGeNRs to be half-metals. The robust half-metallic state of Cr adsorbed AGeNRs can be used in spintronic devices.