Smectic A – Smectic C* Transition in a “de Vries” Liquid Crystal by ²H NMR

Abstract

Solid State ²H Nuclear Magnetic Resonance (NMR) spectroscopy was applied to the structural and orientational studies of a selectively labelled ‘de Vries’ liquid crystal compound. Measurements were performed at five values of the magnetic field, ranging from 4.70 to 18.80 T. The trend of the orientational order S and tilt angle θ of the ²H-labeled moiety in the SmA and SmC* phases at different magnetic fields confirms previous results and allows us to better characterize the SmA-SmC* transition.

Keywords:

• Liquid crystal
• de Vries
• Phase transition
• Tilt
• Order
• NMR

Acknowledgments

We acknowledge the support of Egide (programme Galilée), from the Università Italo-Francese (Programma Galileo 2009/2010). This work was partially funded by the COST D35 WG13–05 project (between the Italian and Czech groups). We would like to thank Dr. Sergey V. Dvinskikh for NMR measurements at 4.70 T and Prof. Anne Lesage for helpful discussions.