Molecular orientation and dielectric anisotropy properties of 4-cyano-4 '-n-heptylbiphenyl-TiO(2) liquid crystal composite

Okutan M., Yakuphanoglu F., Koysal O., San S. E., Oweimreen G. A.

JOURNAL OF NON-CRYSTALLINE SOLIDS, vol.354, no.30, pp.3529-3532, 2008 (SCI-Expanded, Scopus) identifier identifier

  • Publication Type: Article / Review
  • Volume: 354 Issue: 30
  • Publication Date: 2008
  • Doi Number: 10.1016/j.jnoncrysol.2008.03.036
  • Journal Name: JOURNAL OF NON-CRYSTALLINE SOLIDS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.3529-3532
  • Keywords: dielectric properties, relaxation, electric modulus, liquid crystals and molecular liquids, DIPOLE-MOMENT, SPECTROSCOPY
  • Kocaeli University Affiliated: No

Abstract

The molecular orientation and the dielectric anisotropy of the nematic liquid crystal (LC) 4-cyano-4'-n-heptylbiphenyl (7CB) and of TiO(2)-doped 7CB have been investigated. The dielectric properties of the LCs exhibit a relaxation peak that shifts to lower frequencies with increasing voltages. The relaxation frequencies of 7CB and 7CB/TiO(2) liquid crystals were calculated and found to decrease as the bias voltage increases. This is attributed to molecular reorientation. The dielectric anisotropy of the LCs changes from the positive type to negative type and the static electric permittivity and dielectric anisotropy values were found to be lower for the 7CB/TiO(2) system. (C) 2008 Elsevier B.V. All rights reserved.