RT Journal Article
T1 Phase behavior of parallel hard cylinders
A1 Capitán, José A.
A1 Martínez-Ratón, Yuri
A1 Cuesta, José A.
AB We test the performance of a recently proposed fundamental measure density functional of aligned hard cylinders by calculating the phase diagram of a monodisperse fluid of these particles. We consider all possible liquid-crystalline symmetries, namely, nematic, smectic, and columnar, as well as the crystalline phase. For this purpose we introduce a Gaussian parametrization of the density profile and use it to numerically minimize the functional. We also determine, from the analytic expression for the structure factor of the uniform fluid, the bifurcation points from the nematic to the smectic and columnar phases. The equation of state, as obtained from functional minimization, is compared to the available Monte Carlo simulation. The agreement is very good, nearly perfect in the description of the inhomogeneous phases. The columnar phase is found to be metastable with respect to the smectic or crystal phases, its free energy though being very close to that of the stable phases. This result justifies the observation of a window of stability of the columnar phase in some simulations, which disappears as the size of the system increases. The only important deviation between theory and simulations shows up in the location of the nematic-smectic transition. This is the common drawback of any fundamental measure functional of describing the uniform phase just with the accuracy of scaled particle theory.
PB American Institute of Physics
SN 0021-9606 (Print)
SN 1089-7690 (Online)
YR 2008
FD 2008-05-21
LK https://hdl.handle.net/10016/6984
UL https://hdl.handle.net/10016/6984
LA eng
NO 8 pages, 5 figures.-- PACS nrs.: 61.30.-v, 64.70.mf, 64.30.Jk, 65.20.Jk.-- ArXiv pre-print available at: http://arxiv.org/abs/0804.0189
NO Final publisher version available Open Access at: http://gisc.uc3m.es/~cuesta/papers-year.html
NO J. A. Capitán acknowledges financial support through a contract from Consejería de Educación of Comunidad de Madrid and Fondo Social Europeo. Y. M.-R. was supported by a Ramón y Cajal research contract. This work is part of research projects MOSAICO of the Ministerio de Educacióny Ciencia (Spain), and MOSSNOHO of Comunidad Autónoma de Madrid (Spain).
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