Use of dielectric spectroscopy for evidencing subphases in an antiferroelectric liquid Crystal

The analysis of an orthoconic antiferroelectric liquid-crystalline mixture, using dielectric spectroscopy,has revealed a plurality of ferroelectric smectic C* subphases. A great variety of relaxation responsesthat could indicate the presence of different SmC* subphases has been observed with the differentialscanning calorimetry (DSC) technique in partial agreement with other techniques as DSC and opticalmicroscopy. They represent smectic intermediate variants between the ferroelectric phase and theantiferroelectric one, whose study is still open and is collecting a lot of interest in academic field. Theresults obtained by dielectric spectroscopy were compared with other techniques as differentialscanning calorimetry and polarized optical microscopy. The results demonstrate the possibility ofusing dielectric spectroscopy to highlight subphases that cannot be observed with conventionalexperimental techniques.