SURFACE MOLECULAR RELAXATION IN SMECTIC C-ASTERISK PHASE AS STUDIED BY DIELECTRIC-SPECTROSCOPY

The molecular relaxation process of a ferroelectric liquid crystal wit h a high tilt angle and a high spontaneous polarization in a homeotrop ically aligned cell has been studied by the dielectric relaxation meth od in the frequency range 10 Hz to 10 MHz. The measurements have been done using thin (3.5 mu m) cells with gold coated electrodes and sampl es aligned by a magnetic field. It has been observed that the molecula r relaxation around the short axis of the molecule is detected in the chiral nematic and smectic C phases. The surface molecular process is observed in the S-C phase down to nearly 6 to 7 K below the transiti on temperature of the N to the S-C* phase. The experimental results o f the surface molecular process are analysed by theoretical calculatio ns. The experimental results agree with the theoretical predictions.