Coupling of liquid crystalline and polymer network properties in LC-elastomers

Electromechanical and electro-optical properties which result from an interplay of ferroelectricity and elasticity in slightly crosslinked ferroelectric liquid crystalline elastomers are studied in the vicinity of the smectic C*-smectic A* phase transition. In the chiral smectic C* phase, the formation of the network during the crosslinking procedure stabilizes the polar orientation which is present. On heating the smectic C* network into the chiral smectic A* phase, an induced tilt is observed (mechanoclinic effect). The internal mechanical stress induced by the network formation appears to act like an external electric bias-voltage. The results are discussed in terms of a simple Landau model.