Dielectric Properties of Liquid Crystalline Isothiocyanato-tolane Derivatives with Fluorine Atom at Various Lateral Positions

• Authors: J. Czub , S. Urban , R. Dąbrowski , B. Gestblom
• Languages of publication: EN

Abstracts

EN

Dielectric studies were performed for several isothiocyanato-tolane compounds having the F atom attached to the benzene rings at different lateral positions and the alkoxy or alkyl chain at the p-position. They form the nematic phase in broad temperature intervals. The static as well as dynamic properties of the compounds in the nematic and isotropic phases were studied. Tensor permittivity components: ε_ǁ, ε_⊥, Δε, as functions of temperature were measured. The complex dielectric permittivity, ε^*(f)=ε'(f)-iε''(f), was measured in the frequency range of 1 kHz - 3 GHz from which the relaxation times τ_ǁ and τ_⊥ were calculated. The order parameter S(T) was determined from the dielectric data. It was found that the close vicinity of the F atom and the alkoxy group results in blocking of the internal rotation of the wing around the O-phenyl bond.

Keywords

EN

64.70.Md; 77.22.Gm; 77.84.Nh

Discipline

• 77.22.Gm: Dielectric loss and relaxation
• 77.84.Nh: Liquids, emulsions, and suspensions; liquid crystals(for structure of liquid crystals, see 61.30.-v)

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 2005
• Volume: 107
• Issue: 6
• Pages: 947-958

Dates

published

2005-06

received

2005-01-12

Contributors

author

J. Czub

• Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Kraków, Poland

author

S. Urban

• Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Kraków, Poland

author

R. Dąbrowski

• Institute of Chemistry, Military University of Technology, Kaliskiego 2, 00-908 Warsaw, Poland

author

B. Gestblom

• Institute of Physics, Uppsala University, Uppsala, Sweden

References

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Identifiers

DOI

10.12693/APhysPolA.107.947