Combined surface x-ray diffraction and density functional theory study of the germanene/Al(111)- (7×7)R19.1∘ structure

Several papers have reported the epitaxial growth of germanene, a honeycomb layer of Ge atoms. However, these studies are controversial due to a lack of precise structural analyses. Here, the authors combine surface x-ray diffraction with density functional theory calculations to demonstrate that Ge deposited on Al(111) at room temperature forms a surface alloy, organized in a Ge${}₃$Al${}₃$ honeycomb structure, and not a germanene layer as previously reported.