New investigation on the tetragonal liquid-crystalline phase or SmQ.

Chiral liquid crystals, for which twist and smectic order strongly compete, can exhibit complex architectures. This is the case of the SmQ phase which shows a high degree of 3D order (tetragonal or hexagonal) as well as a liquid signature. We have combined X-ray scattering and optical observations on a new compound exhibiting a SmQ phase to discriminate between the two models proposed by A.M. Levelut et al. (J. Phys. II 7, 981 (1997)) at the molecular level for the phase with the I4(1)22 space group.