Final projectile charge states are experimentally and theoretically analyzed after ${\mathrm{H}}^{+}$ ions collide with a ${\mathrm{C}}_{60}$ monolayer deposited on Cu(111) with an ample range of incoming energies (2–8 keV) in the low-energy regime. The three possible charge states (negative, positive, and neutral) are experimentally measured by using the low-energy ion scattering technique for two different collisional setups: 45° (90°) and 67.5° (67.5°) incoming (exit) angles, relative to the target surface plane, with a fixed backscattering angle of 135°. Experimental ion fraction magnitudes and energy dependence are practically intermediate between that found in pristine Cu(111) and a thick ${\mathrm{C}}_{60}$ film, revealing the influence of the substrate on the final charge state of the projectile. Unlike these previous systems, the positive and negative ions contribute nearly evenly to the total scattered charged particles. On the theoretical side, we applied a first-principles based model that considers the fine details of the surface under analysis and assumes a projectile trajectory corresponding to a single binary collision with the more exposed carbon atoms of the ${\mathrm{C}}_{60}$ molecule. The theoretical and experimental results are independently compared with the already reported cases: ${\mathrm{H}}^{+}$ on a thick ${\mathrm{C}}_{60}$ film, ${\mathrm{H}}^{+}$ on Cu(111), and ${\mathrm{H}}^{+}$ on graphite. A detailed analysis of the electronic surface band structure allows us to draw a conclusion about the relevance of the substrate in the present system and about the aspects to be improved in our theoretical description. The contrast between experimental and theoretical results allows us to infer that trajectories involving ion penetration and multiple scattering events are particularly relevant for the projectile-target charge exchange process studied.

中文翻译：

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具有沉积在 Cu(111) 上的 C60 单层的低能质子散射中的电子捕获和损失

最终弹丸电荷状态经过实验和理论分析 ${\mathrm{H}}^{+}$ 离子碰撞 ${\mathrm{C}}_{60}$单层沉积在 Cu(111) 上，在低能量范围内具有足够的输入能量 (2-8 keV)。三种可能的电荷状态（负、正和中性）是通过使用低能离子散射技术对两种不同的碰撞设置进行实验测量的：45°（90°）和 67.5°（67.5°）进入（退出）角，相对于目标表面平面，固定后向散射角为 135°。实验离子分数大小和能量依赖性实际上介于原始 Cu(111) 和厚${\mathrm{C}}_{60}$薄膜，揭示了基材对射弹最终电荷状态的影响。与这些以前的系统不同，正离子和负离子对总散射带电粒子的贡献几乎均匀。在理论方面，我们应用了基于第一性原理的模型，该模型考虑了被分析表面的精细细节，并假设弹丸轨迹对应于与暴露更多的碳原子的单次二元碰撞。${\mathrm{C}}_{60}$分子。将理论和实验结果与已报道的案例独立比较：${\mathrm{H}}^{+}$ 在厚厚的 ${\mathrm{C}}_{60}$ 电影， ${\mathrm{H}}^{+}$ 在 Cu(111) 上，和 ${\mathrm{H}}^{+}$在石墨上。对电子表面能带结构的详细分析使我们能够得出有关衬底在本系统中的相关性以及在我们的理论描述中需要改进的方面的结论。实验和理论结果之间的对比使我们能够推断，涉及离子渗透和多次散射事件的轨迹与所研究的弹丸-目标电荷交换过程特别相关。