MnxGe1−x thin layers studied by TEM, X-ray absorption spectroscopy and SQUID magnetometry

Mn0.06Ge0.94 samples have been grown by molecular-beam epitaxy on Ge(0 0 1)2 × 1. High-resolution transmission electron microscopy shows the coexistence of an ordered diluted Mn0.06Ge0.94 film and of nanoscopic crystallites, which were identified as Mn5Ge3 by electron diffraction. The magnetic properties of the Mn0.06Ge0.94 samples show a superposition of a paramagnetic behavior, due to the interaction of Mn atoms diluted in the Ge host, and a ferromagnetic behavior attributed to the Mn5Ge3 crystallites dispersed into the films. The Mn L2,3 X-ray absorption spectra of the Mn0.06Ge0.94 films exhibit a lineshape typical of metallic Mn, with considerably reduced multiplet structure.