Phase separation and dilution in implanted MnxGe1-x alloys

The structural and electronic properties of MnxGe1-x alloys (x <= 0.15) fabricated by ion implantation are investigated by means of x-ray diffraction and synchrotron radiation photoemission spectroscopy. The diffraction patterns point to the presence of ferromagnetic Mn5Ge3 nanoparticles; however, valence band spectra, interpreted by means of accurate ab initio calculations including Hubbard-like correlations, show clear fingerprints of an effective substitutional Mn dilution in the Ge semiconducting host. (c) 2006 American Institute of Physics.