Charge Exchange in Collisions of Li+ Projectiles Scattered by a K low-covered Graphene Surface

M. A. ROMERO; F. BONETTO; E.A. GARCÍA

Ouro Preto, MG

Encuentro; 2023 Autumn Meeting of the Brazilian Physical Society.; 2023

Brazilian Physical Society

Partial andfinal projectile charge states are theoretically analyzed after Li+ions frontally collide with a single-layer graphene surface with potassiumatoms adsorbed on it, in the very low deposition limit where the adsorbed atomsnegligibly interact with each other.    We applied a model based on first-principles that accounts for allthe details of the surface and is used to describe the resonant charge exchangeprocesses occurring in binary collisions between the projectile and theadsorbate, and between the projectile and the C atoms of the graphene surfacelocated in the surroundings of the adsorption site. Completely differentneutral fractions dependence with the outgoing velocity are found for theprojectiles scattered by the adsorbate and by carbon atoms located far from theadsorbed atom. In addition, an important influence of the adsorbate isperceived in the neutralization of projectiles colliding with the first andsecond set of carbon atoms nearest to the adsorption site. For C atoms locatedat middle range distances (~6.7 Angstroms), the final charge state of the projectile is not affectedby the adsorbate presence, even when an effective interaction between theprojectile and the K adsorbed atom is revealed via appreciable projectile levelwidths.