Hydrogen adsorption configurations on Ge(001) probed with STM

The adsorption of hydrogen on Ge 001 has been studied with scanning tunneling microscopy at 77 K. For low doses 100 L a variety of adsorption structures has been found. We have found two different atomic configurations for the Ge-Ge-H hemihydride and a third configuration that is most likely induced by the dissociative adsorption of molecular hydrogen. The Ge-Ge-H hemihydride is either buckled antiparallel or parallel to the neighboring Ge-Ge dimers. The latter configuration has recently been predicted by M. W. Radny et al. J. Chem. Phys. 128, 244707 2008 , but not observed experimentally yet. Due to the presence of phasons some dimer rows appear highly dynamic.