INVESTIGADORES
BONETTO fernando Jose
artículos
Título:
Charge Transfer in Low-Energy Collisions of Protons with a Thick C 60 Film
Autor/es:
TACCA, M.; QUINTERO RIASCOS, V.; VIDAL, R.; GONZALEZ, C.; BONETTO, F.; GOLDBERG, E. C.
Revista:
JOURNAL OF PHYSICAL CHEMISTRY C
Editorial:
AMER CHEMICAL SOC
Referencias:
Año: 2020 vol. 124 p. 3632 - 3643
ISSN:
1932-7447
Resumen:
Charge exchange processes incollisions between H+ projectiles and a three monolayer C60film grown on Cu(111) are experimentally and theoretically analyzed for a widerange of energies (2-8keV) in the low-energy regime. The negative, positive andtotal projectile scattered ion fractions are experimentally determined by usingthe low energy ion scattering (LEIS) technique. Twodifferent collisional setups are studied for a fixed backscattering angle of135o: 45°/90° and 67.5°/67.5° incoming/exit angles, determined withrespect to the target surface plane.Total ion fractionsbetween 10% and 20% are experimentally found in the whole energy rangeanalyzed, with a slight but sustained increase with the projectile incomingenergy. Positive ions were measured to be the majority of the total scatteredcharged projectiles in almost the whole energy range analyzed. Only for verylow incoming energies (2-3 keV), the positive and negative ion fractions becomecomparable. A first-principles basedtheoretical model is used to describe the dynamic charge exchange processestaking place in the experimental collisional situation. A good description of theexperimental results is obtained in the studied energy range. The theoreticaland experimental results are also analyzed in comparative terms with previousmeasurements in the H+/HOPG system. The differences in the measuredion fractions can be directly related to differences in the electronicstructures of C60 and HOPG.