Abstract
Linear and nonlinear dielectric measurements under dc electric fields have been performed in an antiferroelectric liquid crystal MHPOCBC to obtain a deeper insight of dynamic properties related to a field-induced phase, designated as , appearing when subjected to electric fields in the
phase. We observed a tricritical point in the
phase transition. We found two low frequency modes coming from domain walls in the first-order phase transitions to
and to SmC. In the third-order nonlinear dielectric measurements another low frequency mode was observed, of which frequency decreases near the
transition point. This may be the soft mode responsible for the field-induced transition.
Acknowledgments
We would like to thank Showa Shell Sekiyu Co. Ltd. for supplying MHPOCBC. This work was supported by KAKENHI (Grant-in-Aid for Scientific Research) on Priority Area “Soft Matter Physics” and Scientific Research (C) (19540326) from the Ministry of Education, Culture, Sports, Science and Technology of Japan.