Dielectric Properties of Ferroelectric Liquid Crystals with Diversified Molecular Structure

• Authors: J. Czerwiec , R. Dąbrowski , M. Żurowska , D. Ziobro , S. Wróbel
• Languages of publication: EN

Abstracts

EN

Mesomorphic, thermodynamic, electro-optic and dielectric properties of three homologues of fluorosubstituted esters are described. Full chemical names of these compounds are as follows: (S)-(+)-4-(1-metyl-hepty-loksy)benzoate-(6-penta-fluoro-propano-ynloxyhex-1-oxy)-biphenyl-4-yl (in short 2F6BBiOC8), (S)-(+)-4-(1-metyl-hepty-loksy)benzoate-(6-nona-fluoro-pentano-yloxyhex-1-oxy)-biphenyl-4-yl (in short 4F6BBiOC8), (S)-(+)-4-(1-metyl-hepty-loksy)benzoate-(6-trideca-fluoro-heptano-yloxyhex-1-oxy)-biphenyl-4-yl (in short 6F6BBiOC8). The compounds exhibit ferroelectric smectic C* phase between crystalline and isotropic phase. Only one compound (6F6BBiOC8) shows antiferroelectric phase (SmC*_{A}) observed by dielectric spectroscopy, but the range of this phase is narrow of about 2°. All three compounds exhibit in the SmC* phase Goldstone mode and Maxwell-Wagner relaxation hidden in the conductivity contribution at low frequencies, whereas in the SmC* _{A} phase two anti-ferroelectric modes (AFM1) and (AFM2) contribute to the dielectric spectrum. The compounds were studied using differential scanning calorimetric, frequency domain dielectric spectroscopy, and reversal currents method to determine spontaneous polarization.

Keywords

EN

77.84.Nh; 78.15.+e; 64.70.M-

Discipline

• 77.84.Nh: Liquids, emulsions, and suspensions; liquid crystals(for structure of liquid crystals, see 61.30.-v)
• 78.15.+e: Optical properties of fluid materials, supercritical fluids and liquid crystals(for reactions in supercritical fluids, see 82.33.De)
• 64.70.M-: Transitions in liquid crystals

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 2010
• Volume: 117
• Issue: 4
• Pages: 553-556

Dates

published

2010-04

Contributors

author

J. Czerwiec

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

author

R. Dąbrowski

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

author

M. Żurowska

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

author

D. Ziobro

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

author

S. Wróbel

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

References

• 1. R. Dąbrowski, Ferroelectrics 243, 1 (2000)
• 2. A. Mikułko, M. Marzec, S. Wróbel, R. Dąbrowski, Opto-Electron. Rev. 14, 319 (2006)
• 3. M. Marzec, A. Mikułko, S. Wróbel, A. Szymańska, R. Dąbrowski, Mol. Cryst. Liq. Cryst. 480, 140 (2008)
• 4. A. Mikułko, M. Marzec, M.D. Ossowska-Chruściel, J. Chruściel, S. Wróbel, Ferroelectrics 343, 209 (2006)
• 5. S. Wróbel, W. Haase, A. Fąfara, M. Marzec, in: Relaxation Phenomena, Liquid Crystals, Magnetic Systems, Polymers, High-T$_c$ Superconductors, Metallic Glasses Eds. S. Wróbel, W. Haase, Springer-Verlag, Heidelberg 2003, Ch. 5.11

Identifiers

DOI

10.12693/APhysPolA.117.553