Computer simulations of sputtering and fragment formation during keV C₆₀ bombardment of octane and β-carotene

Molecular dynamics computer simulations are used to investigate material ejection and fragment formation during keV C60 bombardment of organic solids composed from small (octane) and medium (β-carotene)-sized organic molecules. Both systems are found to sputter efficiently. For the octane system, material removal occurs predominantly by ejection of intact molecules, whereas fragment emission is a main ejection channel for β-carotene. A difference in the molecular dimensions is proposed to explain this observation. Fragment formation is investigated to answer the question why so few fragments remain in the bombarded solid.