Recovery of a reversed phase sequence in one ternary liquid-crystal-mixture system

Abstract

The $n\text{OHFBBB}1\text{M}7$ $(n=10)$ compound, 10OHF, shows a reversed $\text{Sm}{C}_{FI2}^{\ensuremath{\ast}}\text{-Sm}{C}^{\ensuremath{\ast}}$ phase sequence, unique among all known antiferroelectric liquid crystals. This reversed phase sequence is stabilized when 10OHF is doped with 9OTBBB1M7(C9) or 11OTBBB1M7(C11). In contrast, doping of the homologous members ($n=9$, 11, or 12) eliminates the $\text{Sm}{C}_{FI2}^{\ensuremath{\ast}}$ phase. One 10OHF/11OHF mixture without the $\text{Sm}{C}_{FI2}^{\ensuremath{\ast}}$ phase was selected for further studies. By adding C9 into this particular mixture, the reversed phase sequence is revived. To our surprise, even though 11OHF destabilizes the $\text{Sm}{C}_{FI2}^{\ensuremath{\ast}}$ phase in binary mixtures with 10OHF, it significantly increases the $\text{Sm}{C}_{FI2}^{\ensuremath{\ast}}$ temperature range in the 10OHF/11OHF/C9 ternary mixtures.