QENS study of molecular motions in partially deuterated liquid crystal 4BT

Abstract

Molecular rotational dynamic in the crystalline and smectic E phases of selectively deuterated (in the outer phenyl ring) 4-n-butyl-isothiocyanatobiphenyl was investigated by means of quasielastic neutron scattering. The 120° reorientation of the methyl group in the crystal phase could be identified at 125 K. Additionally, ring flips were seen at 200 K. The structure of crystal and smectic E phases was obtained by X-ray measurements and the data give the identification of type of solid phases.

Keywords:

• liquid crystals
• quasielastic neutron scattering
• elastic incoherent structure factor
• X-ray

Acknowledgements

The authors would like to thank Prof. Maria Massalska-Arodź from the Institute of Nuclear Physics PAN, for discussion, and Dr M. Gonzalez for help in the neutron measurements at Institut Laue Langevin, Grenoble.

Disclosure statement

No potential conflict of interest was reported by the authors.

Note

1. The X-ray diffraction measurements were carried out in the laboratory of structure analysis IFJ PAN; instrument scientist: Prof. Andrzej Budziak.