Microscopic Aspects of the Smectic Phases

1992 ◽  
pp. 29-39 ◽  
Author(s):  
W. H. de Jeu
Keyword(s):  
Smectic Phases

Freeze-fracture TEM of the helical smectic A* phase

1992 ◽  
Vol 50 (1) ◽  
pp. 278-279
Author(s):  
K.J. Ihn ◽  
R. Pindak ◽  
J. A. N. Zasadzinski
Keyword(s):  
Liquid Crystal ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Freeze Fracture ◽  
Smectic Phase ◽  
Layer Spacing ◽  
Screw Dislocations ◽  
Smectic A ◽  
Smectic Phases ◽  
Discrete Amount

A new liquid crystal (called the smectic-A* phase) that combines cholesteric twist and smectic layering was a surprise as smectic phases preclude twist distortions. However, the twist grain boundary (TGB) model of Renn and Lubensky predicted a defect-mediated smectic phase that incorporates cholesteric twist by a lattice of screw dislocations. The TGB model for the liquid crystal analog of the Abrikosov phase of superconductors consists of regularly spaced grain boundaries of screw dislocations, parallel to each other within the grain boundary, but rotated by a fixed angle with respect to adjacent grain boundaries. The dislocations divide the layers into blocks which rotate by a discrete amount, Δθ, given by the ratio of the layer spacing, d, to the distance between grain boundaries, lb; Δθ ≈ d/lb (Fig. 1).

Induced smectic phases

1978 ◽  
Vol 3 ◽  
pp. 403-407 ◽  
Author(s):  
B. Engelen ◽  
G. Heppke ◽  
R. Hopf ◽  
F. Schneider
Keyword(s):  
Smectic Phases ◽  
Induced Smectic Phases

X-ray scattering by 1D molecular Guinier-Preston zones in ordered smectic phases

1992 ◽  
Vol 2 (6) ◽  
pp. 899-913 ◽  
Author(s):  
Patrick Davidson ◽  
Elisabeth Dubois-Violette ◽  
Anne-Marie Levelut ◽  
Brigitte Pansu
Keyword(s):  
X Ray ◽  
X Ray Scattering ◽  
Smectic Phases ◽  
Ray Scattering

First optical observation of Kossel diagrams in chiral smectic phases

1990 ◽  
Vol 51 (18) ◽  
pp. 2087-2099 ◽  
Author(s):  
H.-S. Kitzerow ◽  
G. Heppke ◽  
H. Schmid ◽  
B. Jérôme ◽  
P. Pieranski
Keyword(s):  
Optical Observation ◽  
Smectic Phases

Microscopic ordering in smectic phases of liquid crystals

1990 ◽  
Vol 51 (18) ◽  
pp. 2015-2022 ◽  
Author(s):  
M. Zgonik ◽  
M. Rey-Lafon ◽  
C. Destrade ◽  
C. Leon ◽  
H.T. Nguyen
Keyword(s):  
Liquid Crystals ◽  
Smectic Phases

Evidence of two new ordered smectic phases in ferroelectric liquid crystals

1978 ◽  
Vol 39 (5) ◽  
pp. 548-553 ◽  
Author(s):  
J. Doucet ◽  
P. Keller ◽  
A.M. Levelut ◽  
P. Porquet
Keyword(s):  
Liquid Crystals ◽  
Ferroelectric Liquid Crystals ◽  
Smectic Phases

Induced Smectic Phases II. Influence of the Amino Substituent on the Induction of Smectic Phases

1981 ◽  
Vol 36 (10) ◽  
pp. 1086-1091 ◽  
Author(s):  
F. Schneider ◽  
N. K. Sharma
Keyword(s):  
Liquid Crystal ◽  
Electron Donor ◽  
Amino Group ◽  
Donor Property ◽  
Smectic Phases ◽  
Ct Complexes ◽  
Induced Smectic Phases

The diagrams of state have been studied for some liquid crystal mixtures which show the induction of smectic phases. Each of the systems studied contains one component with an amino group which influences the polarity and the electron donor property of the molecules. The discussion of the diagrams of state, of the thickness of the smectic layers and of the colours of the mixtures, which indicate the formation of CT complexes, shows that existing models can not explain the induction of smectic phases.

Induced Smectic Phases I. Polymorphism in Binary Mixtures of Alkyloxybenzylidene-alkylanilines with Alkyl- and Alkyloxy- cyanobiphenyls

1981 ◽  
Vol 36 (1) ◽  
pp. 62-67 ◽  
Author(s):  
F. Schneider ◽  
N. K. Sharma
Keyword(s):  
Chain Length ◽  
Binary Mixtures ◽  
Transition Temperatures ◽  
Mean Values ◽  
Smectic Phases ◽  
The Mean ◽  
Induced Smectic Phases

The diagrams of state of mixtures of 4-n-alkyloxybenzylidene-4'-n-butylanilines with 4-n- alkyl- and 4-n-alkyloxy-4'-cyanobiphenyls are studied. The mixtures form induced smectic phases of type SA, SB and SE. In all three smectic phases the thickness of the smectic layers agrees with the mean values of the molecular lengths. In most cases the induced SA phases do not show uninterrupted miscibility with the SA phases of the pure components. For instance, the system 40 • 4/8 CBP exhibits three separate SA phase areas. The maximum transition temperatures of the induced smectic phases increase with increasing chain length of the azomethines, but remain constant in case of the SA and SB phases or even decrease in case of the SE phases with increasing chain length of the cyanobiphenyls

Sign in / Sign up

Export Citation Format

Share Document