Spreading and orientation of silver nano-drops over a flat graphene substrate: An atomistic investigation

The spreading and orientation of silver nano-drop over the graphene substrate are important in various applications such as flexible electronic, bio-medical, electrochemical, and coating materials, etc and have been explored by molecular dynamics simulations. The tuning of interaction energy parameter between graphene and silver affects both spreading and phase transitions of silver nano-drop over the graphene substrate. At high interaction energy, silver nano-drops spread over the graphene substrate and solidified at a higher temperature compared to lower interaction energies. Silver depicts fcc with a layered hcp structure over the graphene substrate during cooling from 1500 K to 10 K. However, at the interface between graphene and silver nano-drop, silver shows the fcc{111} planner orientations. Spreading and orientation of silver nano-drop over the graphene substrate has been characterized by estimation of interaction energies, average number distributions, bond order parameters, the percentage of a crystalline atom during solidification. The results suggest that the silver nano-drop depicts the unique crystal structure with high thermal stability over the graphene substrate compared to the bulk. Therefore, it is extremely desirable material for the development of an efficient catalyst and flexible electronic circuits.