Prediction of mechanical properties of 2D solids with related bonding configuration

Abstract

Our knowledge of the mechanical behavior of 2D solids lags far behind the information available on their electronic properties, despite their relevance for any technological application. A chemistry-based reference model is introduced that allows the unknown mechanical properties to be estimated from a limited data base for groups of atomic and molecular monolayers with similar bonding configuration. This nanometrological approach is demonstrated for the well-studied graphene-like monolayers boronitrene and phosphorene, and the group IV-A monolayers graphene, silicene, germanene, and stanene with hexagonal structure. Comparable results were obtained for the less studied group VI-B molecular layers WS₂, MoS₂, WSe₂, MoSe₂, WTe₂, and MoTe₂. With the ratios of a known property of the group members to that of the reference compound, unknown fracture properties were extracted using a prototype for calibration of this property. The reference model yields very good agreement with existing data for the graphene-like monolayers. For the transition metal dichalcogenides (TMDs) results are still needed for a detailed comparison. The model can be applied to any group of atomic- and molecular layers with a related bonding configuration and stoichiometry. In view of the fast-growing family of 2D solids, the chemical reference model will provide a versatile tool to estimate unknown fracture properties from a minimal data base.