Molecular dynamics investigation on the nano-mechanical behaviour of C₆₀ fullerene and its crystallized structure

C₆₀ fullerene has been utilized in various applications, including low friction and wear coatings, due to its unique molecular structure. In this work, molecular dynamics simulations were conducted to assess the nano-mechanical behaviour of a single C₆₀ fullerene and its crystallized structure. A single C₆₀ model and a model of a face-centred cubic structured C₆₀ crystal with a one-unit-cell thickness were prepared for compression and unloading simulations based on the adaptive intermolecular reactive empirical bond-order potential for carbon. Force-displacement curves and molecule-averaged virial stresses were obtained during the simulation. The models applied during the compression and unloading processes were visualized to confirm the deformation behaviour. Both the single and crystal C₆₀ models showed a perfectly reversible deformation before the point of force decrease that occurred during compression. In particular, the face-centred cubic structure of the crystal C₆₀ model was severely altered during compression before the individual C₆₀ molecules experienced permanent deformation. The maximum values of the normal virial stress in the compression direction before the permanent deformation of the molecules were almost same for both the single and crystallized models.