The d-electron contribution to the stopping power of transition metals

TL;DR

This paper introduces a new non-perturbative model to accurately describe the contribution of d-electrons in transition metals to their stopping power across a wide energy range, aligning well with experimental data.

Contribution

The paper presents a novel non-perturbative approach to model d-electron contributions, improving understanding of transition metals' stopping power at low energies.

Findings

Good agreement with experimental data at low energies

Effective combination with other models for comprehensive energy range coverage

Enhanced understanding of d-electron role in ion stopping processes

Abstract

We present a new non-perturbative model to describe the stopping power by ionization of the $d$-electrons of transition metals. These metals are characterized by the filling of the d-subshell and the promotion of part of the electrons to the conduction band. The contribution of d-electrons at low-impact energies has been noted experimentally in the past as a break of the linear dependence of the stopping power with the ion velocity. In this contribution, we describe the response of these electrons considering the atomic "inhomogeneous" momentum distribution. We focus on the transition metals of Groups 10 and 11 in the periodic table: Ni, Pd, Pt, Cu, Ag, and Au. Results describe the low energy-stopping power, with good agreement with the experimental data and available TDDFT results. By combining the present non-perturbative model for the $d$-subshell contribution with other approaches for the valence electrons and for the inner shells, we provide a coherent theoretical method capable of describing the stopping power of these transition metals from the very low to the high energy region.