Optical studies on free-standing films of an achiral smectic liquid crystal

Employing null transmission ellipsometry and depolarized reflected light microscopy, we have studied two smectic phases, $\mathrm{Sm}-C_1$ and $\mathrm{Sm}-C_2,$ of one achiral mesogen. Our results show that $\mathrm{Sm}-C_1$ and $\mathrm{Sm}-C_2$ are the synclinic $\mathrm{Sm}-C$ and anticlinic $\mathrm{Sm}-C_A$ phases, respectively. We find no evidence to support recent claims that the $\mathrm{Sm}-C_1$ is chiral and ferroelectric [R. Stannarius et al., Phys. Rev. Lett. 90, 025502 (2003)].