The structural transitions of C_(60) nanowhiskers under an electric field characterized by in situ transmission electron microscopy and electron energy-loss spectroscopy

摘要

In situ electrical transport measurements for individual C_(60) nanowhiskers are performed using a transmission electron microscope which monitors the crystal and electronic structural changes of the C_(60) nanowhiskers simultaneously. Electron diffraction combined with electron energy-loss spectroscopy shows that under the external electric current, the C_(60) nanowhiskers first transform from a face-centered-cubic structure to a disordered arrangement of C_(60) molecules. The cage structure of the C_(60) molecules then collapses to an amorphous carbon and finally, the amorphous carbon turns into graphene stacks. This process indicates the hybridization transformation from sp~(2.278) to sp~2, which is different from the transition process of C_(60) materials under high pressure. The obtained results also suggest that the stability of the C_(60) nanowhiskers should be of crucial concern when they work as electrical devices.