Orientational ordering in the chiral smectic-C*FI2 liquid crystal phase determined by resonant polarized x-ray diffraction.
High-resolution resonant polarized x-ray diffraction experiments near the sulfur K edge have been performed on free-standing liquid crystal films exhibiting the chiral smectic-C*FI2 phase. It is widely accepted that this phase has a four-layer repeat unit, but the internal structure of the repeat unit remains controversial. We report different resolved features of the resonant x-ray diffraction peaks associated with the smectic-C*FI2 phase that unambiguously demonstrate that the four-layer repeat unit is locally biaxial about the layer normal and that the measured angle, describing the biaxiality, is in good agreement with optical measurements.
Cady
A
A
School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Pitney
J A
JA
Pindak
R
R
Matkin
L S
LS
Watson
S J
SJ
Gleeson
H F
HF
Cluzeau
P
P
Barois
P
P
Levelut
A M
AM
Caliebe
W
W
Goodby
J W
JW
Hird
M
M
Huang
C C
CC