Study of Dielectric Dispersion in Non-Layer-Shrinkage Liquid Crystal Compounds

Abstract

Measurements of dielectric dispersion have been carried out on two liquid crystal compounds 8422[2F3] and 8O23[7F8-], showing non-layer-shrinkage (NLS) behavior through the smectic-A(Sm-A)-smectic-C (Sm-C) transition. The critical exponent γ determined from the data lies 1.5–1.9 for 8422[2F3], and 1.1–1.2 for 8O23[7F8-]. These results indicate that the Sm-A-Sm-C transition with NLS behavior can exhibit quasi two-dimensional Ising critical behavior under a certain condition.

Keywords:

• Dielectric dispersion
• critical phenomena
• smectic phase
• NLS behavior

Acknowledgments

The authors are grateful to Prof. Hashimoto and Dr. Morikawa for technical support in early stage of the dielectric measurement. The liquid-crystal compounds were kindly provided by 3M Company, St. Paul, Minnesota, USA.