Vertical growth of Mn:Ge nanowires and their magnetic properties

We report on synthesis of Mn-doped Ge nanowires and their magnetic and electrical properties. The vertically aligned Mn:Ge nanowires wer grown on the germanium substrate by vapor-liquid-solid mechanism using Au as catalyst and GeCl₄ and MnCl₂ as precursor. Anomalous X-ray scattering measurement makes it clear that Mn atoms are substitutionally incorporated with the diamond network of host Ge sites. Also X-ray magnetic circular dichroism spectra at Mn L_2,3-edges showed that doped Mn has local spin moment with the 3d⁵ electronic configuration above room temperature, meaning that the ferromagnetism originates from doped Mn²⁺ ions.