New ferroelectric liquid crystalline substances with lateral groups in thecore

New series of ferroelectric liquid crystalline materials containing methyl and methoxy lateral groups on the aromatic ring of the core unit, as well a s non-substituted materials have been synthesised. All compounds exhibit a wide temperature range of the ferroelectric chiral SmC* phase. A low temper ature ferroelectric phase was detected for some of the investigated compoun ds probably composed of the SmC* phase and a crystalline phase. Measurement s of spontaneous polarisation and tilt angle, helical pitch and dielectric permittivity has been performed.