Numéro
J. Phys. France
Volume 51, Numéro 16, août 1990
Page(s) 1749 - 1757
DOI https://doi.org/10.1051/jphys:0199000510160174900
J. Phys. France 51, 1749-1757 (1990)
DOI: 10.1051/jphys:0199000510160174900

Electro-optical and thermal studies of one ferroelectric liquid-crystal compound with a polarization sign reversal

C.C. Huang1, T. Min1, D.S. Lin1, B. Zhou1 et J.W. Goodby2

1  School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, U.S.A.
2  School of Chemistry, The University, Hull HU6 7RX, G.B.


Abstract
Temperature variations of heat capacity, optical tilt angle, polarization, and helical pitch have been measured in the vicinity of the smectic-A (SmA)-chiral-smectic-C (SmC*) transition of one liquid-crystal compound which exhibits an unusual reversal behavior in polarization at about 25 °C while the SmA-SmC* transition occurs at 50 °C. Unexpectedly, from our detailed calorimetric and optical microscopy studies, we have found that the recrystallization also occurs around 25 °C during a reasonably slow cooling experimental run.

PACS
7820J - Electrooptical effects.
7722 - Dielectric properties of solids and liquids.
6520 - Thermal properties of liquids: heat capacity, thermal expansion, etc..
6470M - Transitions in liquid crystals.

Key words
dielectric polarisation -- dielectric properties of liquids and solutions -- electro optical effects -- ferroelectric liquid crystals -- liquid crystal phase transformations -- molecular orientation -- optical microscopy -- recrystallisation -- smectic liquid crystals -- specific heat of liquids