Thickness dependent phase behavior of antiferroelectric liquid crystal films.
Free standing films of a liquid crystal compound with simple surface enhanced order were studied. The resultant phase diagram demonstrates that (1) the short helical pitch smectic-C(alpha)* phase disappears below a film thickness of 10 layers, and (2) the temperature window of a distorted 4 layer smectic-C(FI2)* phase increases dramatically upon decreasing film thickness. The experimental findings were attributed to the reduced dimensionality and enhanced surface effects in thin films. The results of the smectic-C(alpha)* phase are consistent with what have been reported for helically ordered magnetic thin films, with a noticeable difference due to the opposite effect of the surface on ordering in the two systems.
Pan
LiDong
L
School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Wang
Shun
S
Hsu
C S
CS
Huang
C C
CC