Critical fluctuations at the untilted-tilted phase transition in chiral smectic liquid crystals
The layer compression modulus B was measured near the Sm-A-Sm-C* and Sm-A-Sm-C(*)(A) transitions of chiral smectic liquid crystals. B shows a marked pretransitional softening due to the order parameter fluctuations above the phase transition. The width of the critical region of the Sm-A-Sm-C* and Sm-A-Sm-C(*)(A) transitions is smaller than that of the Sm-A-Sm-C(*)(alpha) transition. The critical exponents of B are in agreement with the theoretical description based on renormalization-group method. These results reveal that these transitions are not of the Landau mean-field type.
Shibahara
S
Department of Organic and Polymeric Materials, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo 152, Japan.
Yamamoto
J
Takanishi
Y
Ishikawa
K
Takezoe
H