On the local density dependence of electronic stopping of ions in solids

JOURNAL OF NUCLEAR MATERIALS

卷:507

Article

Caro, M.¹  Tamm, A.²  Correa, A. A.²  Caro, A.³ 

[1] Virginia Polytech Inst & State Univ, Dept Mech Engn, Falls Church, VA 22043 USA

[2] Lawrence Livermore Natl Lab, Quantum Simulat Grp, Livermore, CA 94550 USA

[3] George Washington Univ, Ctr Sci & Technol, Ashburn, VA 20147 USA

关键词: Time dependent density functional theory;    Binary collisions;    Electronic stopping power;    Nickel;   

DOI  :  10.1016/j.jnucmat.2018.04.019

来源: Elsevier

【 摘 要 】

We use time-dependent density functional theory to calculate the electronic stopping S-e in binary Ni-Ni atomic collisions and for a Ni projectile along channeling directions in a Ni crystal. Our results show that when S-e is reported as a function of the ground state target electronic density rho(0) the stopping is not a single-valued function of the local density, as assumed in formalisms that date back to the origins of quantum mechanics, but shows loops, suggesting that it is inaccurate to model stopping as a dissipative force of the type F = beta(rho(0))v, as it is customarily done in non-adiabatic molecular dynamics simulations of ion-solid interactions. We compare our results with S-e in a uniform electron gas where the above definition for the force holds, and conclude on the validity of using jellium as a crude approximation for more realistic inhomogeneous electron gases. (C) 2018 Elsevier B.V. All rights reserved.

【 授权许可】

Free