Title:	Pressure induced twist grain boundary phase
Authors:	Krishna Prasad, S. Nair, Geetha G. Chandrasekhar, S. Goodby, J.W.
Issue Date:	Feb-1995
Publisher:	Gordon and Breach Science Publishers.
Citation:	Molecular Crystals and Liquid Crystals, 1995, Vol.260, p387-394
Abstract:	We report high pressure studies on a binary system of 4-(2'-methyl butyl)phenyl 4'-n-octyl biphenyl-4-carboxylate (CE8 from BDH) and 4-n- dodecyloxy biphenyl-4'-(2'-methyl butyl)benzoate (C12). For the concentration range 0.32<X<0.62, where X is the weight fraction of C12, the system shows the following sequence of transitions at room pressure: Isotropic- Cholesteric (Ch)-Twist Grain Boundary (TGB)-Smectic A (A)Smectic C- (C*). For X=0.25, the Ch phase transforms directly to the A phase at 1 bar, but there is an induced TGB phase between the Ch and A phases at elevated pressures. Analysis of the topology of the pressure-temperature diagram in the vicinity of the Ch-TGB-A meeting point indicates that is a critical end point rather than a bicritical point as expected from the mean field theory. At X=0.64 there is a direct TGB-C* transition at 1 bar, but there appears a pressure induced A phase between the TGB and C* phases. The topology of the phase diagram suggests that the TGB-A-C* meeting point is a bicritical point.
Description:	Restricted Access.
URI:	http://hdl.handle.net/2289/2322
ISSN:	1058-725X
Alternative Location:	http://dx.doi.org/10.1080/10587259508038712
Copyright:	1995 OPA (Overseas Publishers Association) N.V.
Appears in Collections:	Research Papers (SCM)

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