Atomistic Doping Effects on the Ideal Strength of Graphene/Aluminum Interfaces

Generally, atomic doping is an effective method to address the weak bonding strength of the graphene/aluminum (Gr/Al) composite interface structure caused by physical adsorption, thereby enhancing the mechanical properties of the interface structure. In this paper, the nanoscopic influence mechanisms of atomic (M, including 12 types of atoms (elements)) doping in the aluminum matrix (Al) on the ideal strength of the Gr/Al interface structures are investigated based on density functional theory. The analysis of the electronic properties of the typical interface structures reveals that doping with scandium (Sc), copper (Cu) and manganese (Mn) atoms can all improve the interface binding energy of the Gr/Al structures, but their effects on the ideal strength are different. Sc doping disrupts the symmetry of the graphene structure so as to enhance the interface binding energy, but the ideal strength of the Gr/Al structures is decreased. For Cu doping it shows good compatibility with the Al matrix and the interface binding energy is enhanced through Cu alloying with the Al matrix, while the ideal strength of the interface remains basically unchanged. As for Mn doping, it causes the charge to accumulate around the Mn atoms and a resonance peak between the dZ2 orbitals of Mn and the px orbitals of Al to form, thereby improving the ideal strength of the interface structure. This study provides valuable insights for the design of Gr/Al composites by elucidating the underlying mechanisms for enhancing interface mechanical properties.