  Heteroepitaxial Ge0.98Mn0.02 quantum dots on Si (001) were grown by molecular
beam epitaxy. The standard Ge wetting layer-hut-dome-superdome sequence was
observed, with no indicators of second phase formation in the surface
morphology. We show that Mn forms a dilute solid solution in the Ge quantum dot
layer, and a significant fraction of the Mn partitions into a sparse array of
buried, Mn-enriched silicide precipitates directly underneath a fraction of the
Ge superdomes. The magnetic response from the ultra-thin film indicates the
absence of robust room temperature ferromagnetism, perhaps due to anomalous
intermixing of Si into the Ge quantum dots.
