Ge2Pt hut clusters: A substrate for germanene

Abstract

The formation and structure of Ge2Pt clusters was studied in order to understand their germanene termination layer. The Ge2Pt clusters are formed by depositing a few layers of Pt on a Ge(110) surface. Annealing at temperatures above 1043 K results in eutectic Ge-Pt droplets that etch grooves on the surface in the [11¯0] direction. Upon cooling down, they solidify and decompose into a Ge2Pt phase and a pure Ge phase. Electron diffraction reveals that the hut-shaped clusters have their (001) plane oriented parallel to the Ge(110) surface and their (100) plane facing in the Ge[11¯0] direction. The facets of the Ge2Pt hut clusters have been determined to be the {101} and {011} planes. The germanene layers which cover these facets are commensurate with the {101} and {011} facets of the Ge2Pt substrate.