A unitary picture of the structural properties of MnxGe1 − x diluted alloys fabricated by either ion implantation or molecular beam epitaxy, at various growth temperatures (from 80 to about 623K) and few per cent concentrations, was proposed. Analysis was based on synchrotron radiation X-ray absorption spectroscopy at the Mn K edge. When the growth temperature exceeds 330K, the molecular beam epitaxy samples showed a high number of precipitated ferromagnetic nanoparticles, mainly Mn5Ge3, nucleated from the previous occupation of interstitial tetrahedral sites. Efficient substitution was observed in the case of molecular beam epitaxy samples made by alternate layers of GeMn alloys grown at T ≤ 433K and undoped Ge thick layers. Similar good dilution properties were obtained by implanting Mn ions at low temperatures (80K). Possible precursors to preferential mechanisms in the alloy formation were considered on the basis of the present comparative study.

Localization of the Dopant in Ge:Mn Diluted Magnetic Semiconductors by X-Ray Absorption at the Mn K Edge. R.Gunnella, L.Morresi, N.Pinto, A.Di Cicco, L.Ottaviano, M.Passacantando, A.Verna, G.Impellizzeri, A.Irrera, F.d'Acapito: Journal of Physics - Condensed Matter, 2010, 22[21], 216006