Ge<inf>1-x</inf> Mn<inf>x</inf> Clusters: Central structural and magnetic building blocks of nanoscale wire-like self-assembly in a magnetic semiconductor

Abstract

Controlled nanoscale self-assembly of magnetic entities in semiconductors opens novel perspectives for the tailoring of magnetic semiconductor films and nanostructures with room temperature functionality. We report that a strongly directional self-assembly in growth direction in Mn-alloyed Ge is due to a stacking of individual Ge1-x Mnx clusters. The clusters represent the relevant entitles for the magnetization of the material. They are formed of a core-shell structure displaying a Mn concentration gradient. While the magnetic moments seem to be carried by the shells of the clusters, their core is magnetically inactive. © 2009 American Chemical Society.