Decay and fusion as two different mechanisms of stability loss for the (C_20)_2 cluster dimer

TL;DR

This study investigates the thermal stability of the (C_20)_2 fullerene dimer, revealing two distinct mechanisms—decay and fusion—that influence its metastability at high temperatures.

Contribution

It identifies and quantifies two different processes affecting the stability of the (C_20)_2 dimer, providing activation energies and frequency factors for each mechanism.

Findings

Decay process has an activation energy of 3.4 eV.

Fusion process has an activation energy of 2.7 eV.

Finite lifetime depends on temperature and these two mechanisms.

Abstract

The thermal stability of the (C_20)_2 cluster dimer consisting of two C_20 fullerenes is examined using a tight-binding approach. Molecular dynamics simulations of the (C_20)_2 dimer at temperatures T = 2000 - 3500 K show that the finite lifetime \tau of this metastable system is determined by two fundamentally different processes, the decay of one of the C_20 fullerenes and the fusion of two C_20 fullerenes into the C_40 cluster. The activation energies for these processes Ea = 3.4 and 2.7 eV, respectively, as well as their frequency factors, have been determined by analyzing the dependence of \tau on T.