Oscillatory behavior of gigahertz oscillators based on multiwalled carbon nanotubes

Mechanical oscillatory behavior of multiwalled carbon-nanotube-based oscillators is investigated using molecular-dynamics simulations. The second-generation reactive bond-order potential and a Morse-type van der Waals potential based on the local-density approximation are used to describe bonding and nonbonding atomic interactions, respectively. It is found that the oscillatory frequency saturates as the number of outer tubes reaches three. The simulations show that the oscillatory frequency, amplitude decay rate, and stability of the oscillators depend on the diameter and helicity of the outer tubes, the extrusion distance, as well as the length of the outer tubes.