Ge(1-x) Mn(x) clusters: central structural and magnetic building blocks of nanoscale wire-like self-assembly in a magnetic semiconductor.
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 Ge(1-x)Mn(x) clusters. The clusters represent the relevant entities 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.
Bougeard
D
D
Walter Schottky Institut, Technische Universitat Munchen, Am Coulombwall 3, D-85748 Garching, Germany. bougeard@wsi.tum.de
Sircar
N
N
Ahlers
S
S
Lang
V
V
Abstreiter
G
G
Trampert
A
A
Lebeau
J M
JM
Stemmer
S
S
Saxey
D W
DW
Cerezo
A
A