Heads or tails: how do chemically substituted fullerenes melt?
File(s)
Accepted version
Published version
Author(s)
Armstrong, J
Mukhopadhyay, S
Bresme, F
Fernandez-Alonso, F
Type
Journal Article
Abstract
We address the question as to whether the melting of chemically substituted fullerenes is driven by the dynamics of the fullerene moiety (the head) or the substituted sub-unit (the tail). To this end, we have performed quasielastic neutron-scattering experiments and classical molecular-dynamics simulations as a function of temperature on the prototypical fullerene derivative phenyl-C61-butyric acid methyl ester. To enable a direct and quantitative comparison between experimental and simulation data, dynamic structure factors for the latter have been calculated from atomic trajectories and further convolved with the known instrument response. A detailed analysis of the energy- and momentum-transfer dependence of this observable in the quasielastic regime shows that melting is entirely driven by temperature-activated tail motions. We also provide quantitative estimates of the activation energy for this process as the material first enters a plastic-crystalline phase, followed by the emergence of a genuine liquid at higher temperatures.
Date Issued
2016-04-12
Date Acceptance
2016-04-12
Citation
Physical Chemistry Chemical Physics, 2016, 18, pp.17202-17209
ISSN
1463-9084
Publisher
Royal Society of Chemistry
Start Page
17202
End Page
17209
Journal / Book Title
Physical Chemistry Chemical Physics
Volume
18
Copyright Statement
This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence.
License URL
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Science and Technology Facilities Council (STFC)
Grant Number
EP/J003859/1
PO 4070099066
Subjects
Chemical Physics
02 Physical Sciences
03 Chemical Sciences
Publication Status
Published