The phase behaviour of 4-n-pentylphenyl-4′- n-heptyloxythiobenzoate

Abstract

New results of investigations of phase polymorphism for two substances, hydrogenous (7OS5-d₀) and partially deuterated (7OS5-d₂₆) have been presented. On the basis of measurements of the integrated “elastic window” intensity (EL), quasielastic neutron scattering (QNS) spectra and results obtained with the Transmitted Light Intensity (TLI) method, the metastable character of the SmC phase, that at constant temperature always transforms to the crystalline phase Cr₂, has been confirmed. Variations of the EL show a very clear hysteresis effect in the nematic and SmC phases as well as in solid phases. It was confirmed by a phase polymorphism in both investigated substances. Convergence of the EL and TLI methods was shown. The new phase situation of both hydrogenous and partly deuterated liquid crystals is presented.

Acknowledgements

We thank Dr Krzysztof Lipiński for preparing the chain deuterated compound and Dr Wojciech Zając for assistance during the preparation of the manuscript.

This work was partly supported by the Polish Ministry of Scientific Research and Information Technology, Grant No. 4 T09A 200 25.