Field-induced molecular reorientation keeping a frustrated structure in an achiral bent-shaped liquid crystal

Abstract

The layer and molecular orientational structures have been investigated by X-ray microbeam diffraction and optical birefringence measurements in the frustrated smectic phase of a bent-shaped molecule with two mesogens linked by an alkylene spacer. In the X-ray microbeam measurement, only one diffraction peak indicating (002) was observed in a thin homogeneous cell without an electric field, while two other peaks corresponding to (101) and (101) also appear by applying the field. Moreover, it was also found that the birefringence under an applied field is larger than that without the field. These results led to the conclusion that molecules reorient due to dielectric anisotropy keeping the frustrated structure.

References

1. G. Sigaud, F. Hardouin, M. F. Achard and A. M. Levelut, J. Phys. (France), 1981, 42, 107.
2. K. K. Chan, P. S. Pershan, L. B. Sorensen and F. Hardouin, Phys. Rev. A, 1986, 34, 1420.
3. A. Fukuda, Y. Takanishi, T. Isozaki, K. Ishikawa and H. Takezoe, J. Mater. Chem., 1994, 4, 997.
4. K. Itoh, M. Kabe, K. Miyachi, Y. Takanishi, K. Ishikawa, H. Takezoe and A. Fukuda, J. Mater. Chem., 1997, 7, 407.
5. T. Niori, T. Sekine, J. Watanabe, T. Furukawa and H. Takezoe, J. Mater. Chem., 1996, 6, 1231.
6. D. R. Link, G. Natale, R. Shao, J. E. Maclennan, N. A. Clark, E. Korblova and D. M. Walba, Science, 1997, 278, 1924.
7. T. Niori, PhD Thesis, Tokyo Institute of Technology,Tokyo, 1997.
8. J. Watanabe, T. Niori, T. Sekine and H. Takezoe, Jpn. J. Appl. Phys., 1998, 37, L139.
9. S. W. Choi, M. Zennyoji, Y. Takanishi, H. Takezoe, T. Niori and J. Watanabe(Proceedings of ILCC98, Strasbourg), Mol. Cryst. Liq. Cryst., 1999, in the press.
10. A. Iida, T. Noma and K. Hirano, Ferroelectrics, 1994, 149, 117.
11. Y. Takanishi, A. Iida, K. Ishikawa, H. Takezoe and A. Fukuda, Jpn. J. Appl. Phys., 1996, 35, 683.