Structural, electronic, and magnetic properties of Mn-doped Ge nanowires by ab initio calculations

Using ab initio total energy density-functional theory calculations, we investigated the electronic, structural, and magnetic properties of manganese-doped germanium nanowires. The nanowires have been constructed along the [110] direction and the dangling bonds on the surface have been saturated by hydrogen atoms. We observed that the Mn has lower formation energy at the center of the wire when compared to regions close to the surface. The Mn-Mn coupling has lower energy for a high-spin configuration except when they are first nearest neighbors. These results show that Ge:Mn nanowires are potential candidates for ferromagnetic quasi-one-dimensional systems.