Treating highly charged carbon and fullerene clusters as dielectric particles

Anthony J Stace,Elena Bichoutskaia

doi:10.1039/c1cp21573f

Abstract

A model, recently developed for treating interactions between charged particles of dielectric materials (Bichoutskaia et al., J. Chem. Phys., 2010, 133, 024105), has been applied in an analysis of experimental data on the stability and fragmentation of highly charged carbon and fullerene clusters. Fragmentation data take the form of kinetic energy measurements that accompany the Coulomb fission of highly charged carbon clusters. For many of the examples chosen there is good agreement between the calculated and experimental results; however, the degree of uncertainty in some of the experimental data means that subtle features predicted by the model cannot be verified. When compared with an image charge model, treating carbon particles as a dielectric material reveals significant differences in the nature of the interaction potential.

Highlights

IntroductionFragmentation patterns associated with multiply charged clusters have been the subject of numerous experimental and theoretical studies during the past 30 years.[1,2,3,4,5,6,7,8,9] For weakly bound collections of either atoms or molecules, attempts to observe the process of Coulomb fission in size-selected ions have met with variable success.[3,10,11] In contrast, measurements on the energetics of Coulomb fission in systems with high binding energies, such as multiply charged fullerenes, have been very successful
Several groups have examined the stabilities and energetics of fragmentation of highly charged collections of fullerenes, (C60)zn+,12–14 and there have been a number of measurements reported of the kinetic energy release that accompanies C+ 2 and C+ 4 loss from multiply charged fullerenes and carbon clusters in the range Cz3+ 6 –Cz7+ 0 (z in these studies varies between 2 and 9).[15,16,17,18,19,20]
Eqn (8) is to be compared with eqn (9), which represents an image charge model that is frequently used to analyse the interaction between a point charge and a conducting sphere

Summary

Introduction

Fragmentation patterns associated with multiply charged clusters have been the subject of numerous experimental and theoretical studies during the past 30 years.[1,2,3,4,5,6,7,8,9] For weakly bound collections of either atoms or molecules, attempts to observe the process of Coulomb fission in size-selected ions have met with variable success.[3,10,11] In contrast, measurements on the energetics of Coulomb fission in systems with high binding energies, such as multiply charged fullerenes, have been very successful. There currently exists a wealth of experimental data on the fragmentation of highly charged fullerene and carbon clusters.[12,13,14,15,16,17,18,19,20] This material has a comparatively low dielectric constant (somewhere in the range 3–5), and so the purpose of this publication is to show that a dielectric particle drop model as proposed by Bichoutskaia et al.[26] can give an accurate account of the stability and fragmentation energetics of carbon clusters holding up to eight positive charges

Theory

Results and discussion

Conclusion