Molecular orientation and dielectric anisotropy properties of 4-cyano-4′-n-heptylbiphenyl-TiO2 liquid crystal composite

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

Journal of Non-Crystalline Solids, vol.354, no.30, pp.3529-3532, 2008 (Journal Indexed in SCI Expanded) identifier identifier

  • Publication Type: Article / Review
  • Volume: 354 Issue: 30
  • Publication Date: 2008
  • Doi Number: 10.1016/j.jnoncrysol.2008.03.036
  • Title of Journal : Journal of Non-Crystalline Solids
  • Page Numbers: pp.3529-3532


The molecular orientation and the dielectric anisotropy of the nematic liquid crystal (LC) 4-cyano-4′-n-heptylbiphenyl (7CB) and of TiO2-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/TiO2 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/TiO2 system. © 2008 Elsevier B.V. All rights reserved.