Avtor/Urednik     Žekš, Boštjan; Filipič, Cene; Carlsson, Tomas
Naslov     Theory of ferroelectric liquid crystals
Tip     članek
Vir     Phys Scripta
Vol. in št.     Letnik T25
Leto izdaje     1989
Obseg     str. 362-366
Jezik     eng
Abstrakt     In the ferroelectric helicoidal smectic C* phase the chiral molecules are tilted with their long axes from normal to smectic layers. The directionof the tilt precesses as one goes from one smectic layer to another resulting in a helicoidal structure. The order parameter of the phase transition from the smectic A to the smectic C* phase is the two component tilt vector,which breaks the axial symmetry around the long molecular axis and induces the ordering of transverse molecular dipoles. The extended thermodynamic model is reviewed, which includes the bilinear as well as the biquadratic coupling between the tilt and the transverse polarization and describes in a unified way the thermodynamic properties of these systems. A microscopic model is introduced, which is consistent with the extended thermodynamic model, and the effect of the shape of moleculaes on the macroscopic properties of ferroelectric crystals is estimated.
Deskriptorji     BIOPHYSICS
THERMODYNAMICS
CRYSTALLIZATION
MODELS, THEORETICAL