Mn5Ge3film formation on Ge(111)c(2×8)

Abstract

Thin manganese germanide films with different thicknesses on Ge(111) have been studied in detail by low-energy electron diffraction (LEED), scanning tunneling microscopy, and core-level spectroscopy (CLS). Annealing of the deposited Mn on Ge(111)$c$($2\ifmmode\times\else\texttimes\fi{}8$) between 330--450${}^{\phantom{\rule{0.16em}{0ex}}\ensuremath{\circ}}$C resulted in well-ordered Mn${}_{5}$Ge${}_{3}$ surfaces as seen by intense $\sqrt{3}\ifmmode\times\else\texttimes\fi{}\sqrt{3}$ LEED spots. Up to a coverage of 24 monolayers (ML), island formation is favored. At a coverage of 32 ML, a well-ordered Mn${}_{5}$Ge${}_{3}$ film was found to fully cover the surface. High-resolution Ge 3$d$ CLS spectra were recorded with photon energies between 50 and 110 eV at normal and 60${}^{\ensuremath{\circ}}$ emission angles. In contrast to earlier results, three components have been used in the line-shape analysis to achieve a consistent fit over the energy and angular range. In addition, three components have been identified for the Mn $2p$ CLS spectra. The two major components fit well with a layered Mn germanide structure suggested in the literature.