Sputtering of Fe(100) Substrate Due to Energetic Ion Bombardments: Investigation with Molecular Dynamics Simulations

Molecular dynamics simulations were carried out to investigate physical sputtering of Fe(100) substrate due to energetic ion bombardments. Repulsive interatomic potentials at short internuclear distances were determined with ab initio calculations using the density functional theory. Bohr potentials were fitted to the ab initio results on diatomic pairs (Ar-Fe, Fe-Fe) and used as repulsive screened Coulombic potentials in sputtering simulations. The fitted-Bohr potentials improve the accuracy of the sputtering yields predicted by molecular dynamics for sputtering of Fe(100), whereas Moliere and ZBL potentials were found to be too repulsive and gave relatively high sputtering yields. In spite of assumptions and limitations in this simulation work, the sputtering yields predicted by the molecular dynamics method were in fairly good accordance with the obtainable experimental data in absolute values as well as in manner of the variation according to the Incident energy. Threshold energy for sputtering of Fe(100) substrate was found to be about 40 eV. Additionally, distributions of kinetic energies of sputtered atoms and their original depths could be obtained.

분자 동역학 모사를 이용한 Fe(100) 표면의 스퍼터링 해석