Germanene termination of Ge2Pt crystals on Ge(110)
P Bampoulis1, L Zhang, A Safaei
1Physics of Interfaces and Nanomaterials group, MESA+ Institute for Nanotechnology and University of Twente, PO Box 217, 7500AE Enschede, The Netherlands.
Abstract:
We have investigated the growth of Pt on Ge(1 1 0) using scanning tunneling microscopy and spectroscopy. The deposition of several monolayers of Pt on Ge(1 1 0) followed by annealing at 1100 K results in the formation of 3D metallic Pt-Ge nanocrystals. The outermost layer of these crystals exhibits a honeycomb structure. The honeycomb structure is composed of two hexagonal sub-lattices that are displaced vertically by 0.2 Å with respect to each other. The nearest-neighbor distance of the atoms in the honeycomb lattice is 2.5 ± 0.1 Å, i.e. very close to the predicted nearest-neighbor distance in germanene (2.4 Å). Scanning tunneling spectroscopy reveals that the atomic layer underneath the honeycomb layer is more metallic than the honeycomb layer itself. These observations are in line with a model recently proposed for metal di-(silicides/)germanides: a hexagonal crystal with metal layers separated by semiconductor layers with a honeycomb lattice. Based on our observations we propose that the outermost layer of the Ge(2)Pt nanocrystal is a germanene layer.
Related Concept Videos
01:25Imperfections in Crystal Structure: Point, Line and Plane Defects
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than...
01:26Imperfections in Crystal Structure: Stoichiometric Point Defects