Resonant x-ray scattering study of the antiferroelectric and ferrielectric phases in liquid crystal devices.
Resonant x-ray scattering has been used to investigate the interlayer ordering of the antiferroelectric and ferrielectric smectic C* subphases in a device geometry. The liquid crystalline materials studied contain a selenium atom and the experiments were carried out at the selenium K edge allowing x-ray transmission through glass. The resonant scattering peaks associated with the antiferroelectric phase were observed in two devices containing different materials. It was observed that the electric-field-induced antiferroelectric to ferroelectric transition coincides with the chevron to bookshelf transition in one of the devices. Observation of the splitting of the antiferroelectric resonant peaks as a function of applied field also confirmed that no helical unwinding occurs at fields lower than the chevron to bookshelf threshold. Resonant features associated with the four-layer ferrielectric liquid crystal phase were observed in a device geometry. Monitoring the electric field dependence of these ferrielectric resonant peaks showed that the chevron to bookshelf transition occurs at a lower applied field than the ferrielectric to ferroelectric switching transition.
Matkin
L S
LS
Department of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom.
Watson
S J
SJ
Gleeson
H F
HF
Pindak
R
R
Pitney
J
J
Johnson
P M
PM
Huang
C C
CC
Barois
P
P
Levelut
A M
AM
Srajer
G
G
Pollmann
J
J
Goodby
J W
JW
Hird
M
M