Chiral doping effect in the B2 phase of a bent-core liquid crystal: The observation of resonant X-ray satellite peaks assigned to the 5/10 layer periodic structure

¹ Department of Physics, Kyoto University - Kitashirakawaoiwake-cho, Sakyo-ku, Kyoto, 606-8502, Japan
² Center for Advanced Materials Analysis, Tokyo Institute of Technology - O-okayama, Meguro-ku, Tokyo 152-8550, Japan
³ Photon Factory, Institute of Material Structure Science - 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan
⁴ Department of Organic and Polymeric Materials, Tokyo Institute of Technology - O-okayama, Meguro-ku, Tokyo 152-8550, Japan

^(a) ytakanis@scphys.kyoto-u.ac.jp

Received: 24 November 2014
Accepted: 25 February 2015

Abstract

We studied the details of a local layer structure in the B2 phase of bromo-containing bent-core liquid crystals mixed with a small amount of chiral molecules using microbeam resonant X-ray scattering. In this measurement, we detected the 1 ± 0.2 order satellite peaks, which suggest that the B2 phase of the mixture has a long-range periodic structure. Dielectric and electro-optic measurements indicate almost the same behavior as the antiferroelectric SmC_AP_A(B2) of pure bromo-containing bent-core liquid crystals, so that the B2 phase of the chiral mixture is also antiferroelectric, and it is concluded that the B2 phase of the chiral mixture forms a ten-layer periodic structure. Such a long-range periodic structure did not appear by mixing the racemate of the same compounds, which indicates the chiral effect on the long-range periodic structure.