Molecular orientational ordering in the smectic C* and H* phases of chiral tbaca

In this paper a detailed analysis of 14N NQR experimental data of the chiral liquid crystal TBACA is presented. The effects of the possible orientational ordering of the short molecular axes and of the fluctuations in the direction of the long molecular axis are taken into account. It is shown that in the smectic H* phase polar orientational ordering of the -CH=N-groups exists with the values of ⟨cos ϕ⟩ between∼0.1 and∼0.01. In the smectic C* phase this ordering is even smaller. Anisotropic fluctuations in the direction of the long molecular axes definitely take place in the smectic C* phase.