Description
Carbyne, an infinite linear chain of carbon atoms, is the truly 1D allotrope of carbon that has remained elusive to date. While carbyne like materials like long linear carbon chains encapsulated in carbon nanotubes or short carbon atomic wires are available for study, the transition between the two systems and common properties that can be linked to carbyne are poorly understand. In this talk, I will present our Raman spectroscopy study of the C-mode of individual confined carbyne chains up to the third overtone. We find a strong vibrational anharmonicity that increases with decreasing C-mode frequency. Upon comparison to carbon atomic wires, we find that this relation
between vibrational anharmonicity and C-mode frequency is universal to carbyne-like materials. Finally, I will show that the collective LO-phonon mode of carbon atomic wires confined inside carbon nanotube approaches the frequency of confined carbyne’s C-mode, suggesting that convergence to length-independent properties of long linear carbon chain inside carbon nanotubes occurs at shorter chain lengths than previously thought.
