Back Cover: Au–Ge bonding on a uniformly Au‐covered Ge(001) surface (Phys. Status Solidi RRL 4/2013)

Abstract

The Rapid Research Letter by Dana G. Popescu and Marius A. Husanu (pp. 274–277) reveals the mechanisms acting at the Au/Ge interface, when one single atomic layer (1 ML) of Au is deposited on heated Ge surface. Understanding the nature of the interactions between the ad-atoms and the substrate plays an important role in the context of newly established dimerized surfaces (Si, Ge) as efficient host for the growth of noble metals chains (Pt, Au, Ag). Employing first principles calculations and correlating photoelectron spectroscopy, in both valence and core level regions, with scanning tunneling microscopy, the authors establish that a uniform coverage regime may occur. The surface is featured by symmetric surface dimers, covalently bonded with Au atoms. The metallic character of the surface is due to the Au5d–Ge3s3p hybridized states. The XPS signature of Ge-dimer-bonded Au is documented for the first time in the Au 4f core-level spectra.