Optical studies on the surface-induced tilted layers in freestanding films of two no-layer-shrinkage liquid crystal compounds.
Null transmission ellipsometry has been employed to study the molecular arrangements in freestanding films of two no-layer-shrinkage liquid crystal homologous compounds above the bulk smectic A-smectic C* (Sm C*) transition temperature. An unusual nonplanar-parallel or nonplanar-antiparallel-parallel transition has been observed in both compounds under a proper electric field. With the addition of one CH2 group, while the SmC* phase is more stable thermally, the magnitude of the critical field needed to induce a parallel-antiparallel transition decreases dramatically.
Wang
S T
ST
School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Han
X F
XF
Liu
Z Q
ZQ
McCoy
B K
BK
Huang
C C
CC