Electronic stopping power calculation method for molecular dynamics simulations using local Firsov and free electron-gas models

Abstract Molecular dynamics simulations have proven to be accurate in predicting depth distributions of low-energy ions implanted in materials. Free parameters adjusted for every ion-target combination are conventionally used to obtain depth profiles in accordance with the experimental ones. We have previously developed a model for predicting depth profiles in crystalline Si without free parameters. The electronic stopping power was calculated using local total electron density. The model underestimated the stopping in the ⟨1 1 0⟩ channeling direction. We have now taken a new approach to calculate the electronic stopping power. We use the local valence (3p2) electron density to account for the electronic energy loss between collisions and the Firsov model to account for the electronic energy loss during collision. The lowest electron densities are adjusted with a parametrization that is same for all ions in all implanting directions to correct the problems in the ⟨1 1 0⟩ channeling direction. Keywords: Electronic stoppingRange profileElectron density Acknowledgements The research was supported by the Academy of Finland under projects no. 44215 and 46788. Generous grants of computer time from the Center for Scientific Computing in Espoo, Finland, are gratefully acknowledged. In addition, the authors would like to thank Ms. Susann Toldi for providing a copy of the dissertation of J. Finneman Citation18, Mark Robinson and Ordean Oen.