Molecular Dynamics Simulation of Plasma Surface Interaction

TL;DR

This study uses molecular dynamics simulations to explore hydrogen atom interactions with graphite surfaces, revealing energy-dependent behaviors and the effects of interlayer forces on erosion and molecule formation.

Contribution

A new interlayer potential model for graphite was proposed, enabling detailed MD simulations of plasma-surface interactions and hydrogen erosion processes.

Findings

Hydrogen adsorption varies with incident energy.

Erosion yield increases with interlayer forces.

Chain-structured molecules form during hydrogen interaction.

Abstract

New interlayer intermolecular potential model was proposed and it represented ``ABAB'' staking of graphite. Hydrogen atom sputtering on graphite surface was investigated using molecular dynamics simulation. In the initial short time period, maintaining the flat structure of graphenes, hydrogen atoms brought about the difference interaction process in each incident energy. The first graphene often adsorbed 5 eV hydrogen atoms and reflected almost all of 15 eV hydrogen atoms. The hydrogen atoms which were injected at 30 eV penetrated into the inside of the graphite surface and were adsorbed between interlayer. The desorption of C2H2 on the clear graphite surface was observed in only the case incident at 5 eV. The animation of the MD simulation and radial distribution function indicated that the graphenes were peeled off one by one at regular interval. In common to the incident energy, the yielded molecules often had chain structures terminated by hydrogen atoms. The erosion yield increased compared with the case of no interlayer intermolecular force.