Epitaxial Mn₅Ge₃ nano-islands on a Ge(001) surface

The growth behavior and atomic structure of Mn germanide, grown on Ge(001), is studied with x-ray diffraction and scanning probe microscopy. The amorphous clusters of as-deposited Mn are crystallized into Mn₅Ge₃ nano-islands with a size of ∼100 nm by solid phase epitaxy. At low coverage, the shape of the nano-islands is plateau-like, while at increased coverage it becomes mound-like. At the flat top of the plateau-like nano-islands, the hexagonal atomic structure is resolved. It is interpreted, with the help of first-principles study, as a Mn-terminated Mn₅Ge₃(0001) structure.