Phase transition studies in polymesomorphic compounds |
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| Authors: | S Barocci F Rustichelli S Melone G Torquati V G K M Pisipati N V S Rao |
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| Institution: | (1) Istituto di Fisica, Facoltà di Medicina dell'Università, Ancona, Italia;(2) Sezione di Fisica del Dipartimento di Scienze dei Materiali e della Terra dell' Università Ancona, Italia;(3) Department of Physics, Faculty of Physical Sciences, Nagarjuna University, 522510 Nagarjuna Nagar, India;(4) Department of Chemistry, Faculty of Physical Sciences, Nagarjuna University, 522510 Nagarjuna Nagar, India |
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| Abstract: | Summary The structural parameters of theS
A
andS
B
mesophases and the phase transitionS
G
-S
B
andS
B
-S
A
of the compound N-(p-n-octyloxybenzylidene)p-n-butyl aniline were investigated by X-ray diffraction. This work is complementary
to the previous structural determination in the crystalline solid phase andS
G
phase of the same compound. TheS
B
hexagonal lattice parameters atT=66°C area=b=(5.03±0.01) ? andc=(27.6±0.2) ?. TheS
A
structural data atT=80°C are layer thicknessd=(26.9±0.2) ? and intermolecular distanceD=(5.04±0.05) ?. The interlayer and the in-plane intermolecular distances were obtained as a function of temperature through
all the mesophases. Pretransitional effects were observed at theS
G
-S
B
phase transition, which corresponds to a progressive reduction to zero of the molecule inclination angle with respect to the
normal to the smectic layers. The layer thickness in theS
A
phase appeared smaller than that in theS
B
due to molecular axial fluctuations.
To speed up publication, the authors of this paper have agreed to not receive the proofs for correction. |
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| Keywords: | Phase equilibria phase transitions and critical points of specific substances |
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