  We investigate the local electronic structure and magnetic properties of the
group IV based ferromagnetic semiconductor, GeFe, using soft X ray magnetic
circular dichroism. Our results show that the doped Fe 3d electrons are
strongly hybridized with the Ge 4p states, and have an unusually large orbital
magnetic moment relative to the spin magnetic moment; i.e., morb/mspin = 0.3.
We find that local ferromagnetic domains, which are formed through
ferromagnetic exchange interactions in the high Fe content regions of the GeFe
films, exist at room temperature, well above the Curie temperature. We
demonstrate the first observation of the intriguing nanoscale domain growth
process in which ferromagnetic domains expand as the temperature decreases,
followed by a transition of the entire film into a ferromagnetic state at the
Curie temperature.
