Using a functional C84 monolayer to improve the mechanical properties and alter substrate deformation

Abstract

The nanoindentations of a silicon (111) substrate covered with a manipulated C₈₄ monolayer are explored by molecular dynamics (MD) simulation and further verified by experiments. Calculations show that pop-in events and a stick–slip event are exhibited in the C₈₄/Si substrate during the loading process, where the pop-in events are caused by the severe deformation of the C₈₄ molecule, while the stick–slip event takes place at the interface between the tip and C₈₄ molecule. The resulting deformed conformations and mechanical properties influenced by the diverse indentation mechanisms are also presented. Such a nanoindentation simulation model provides a powerful way to understand at an atomic level the interaction of the parts of an interface, and of the system as a whole. The experimental measurements from ultra-high vacuum atomic force microscopy (AFM) are compared with theoretical findings. Our investigations offer a possible replacement for semiconductor carbide.