Structural studies of cyclohexane in confined geometry by neutron diffraction

Farman, Hossein and Dore, John C. (2008) Structural studies of cyclohexane in confined geometry by neutron diffraction. Chinese Journal of Physics, 46 (1). pp. 73-90. ISSN 0577-9073. (The full text of this publication is not available from this repository)

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Abstract

Neutron diffraction measurements have been made for cyclohexane, C6D12, in the confined geometry of a porous silica with a characteristic pore size of 90 angstrom. The results confirm the large depression of the phase transition temperatures from the liquid to plastic crystal and plastic crystal to brittle crystal phase. The results are compared with some previous studies of phase transitions in bulk cyclohexane. It is found that the structural changes follow a systematic variation similar to that of the bulk phase, only at a lower temperature. However, the Bragg peaks of the solid phase are much broader in the confined geometry, and this behavior is not fully explained by diffraction broadening. It seems that there is increased disorder resulting from the restricted volume of the crystallites and a hysteresis effect dependent on the thermal history of the sample. The defective nature of the lattice, which is related to the coupling of the translational displacement to the local orientation of adjacent molecules, appears to be enhanced for the confined cyclohexane in both the plastic and brittle crystal phases.

Item Type: Article
Subjects: Q Science
Divisions: Faculties > Science Technology and Medical Studies > School of Physical Sciences
Depositing User: Maggie Francis
Date Deposited: 18 Apr 2009 09:07
Last Modified: 04 Jul 2014 11:19
Resource URI: http://kar.kent.ac.uk/id/eprint/13367 (The current URI for this page, for reference purposes)
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