Dielectric properties of a superlattice containing a linear copolysiloxane substituted with aromatic acid side chains Langmuir-Blodgett films

The dielectric behaviour of the Langmuir-Blodgett (LB) superlattice containing linear copolysiloxane is investigated by examining the dielectric loss and capacitance of the superlattice at room temperature (21/spl deg/C) in the frequency range of 10/sup 2/ to 10/sup 3/ Hz. The maximum loss value occurs at a frequency of /spl sim/5000 Hz, which corresponds to a relaxation time of 3.18/spl times/10/sup -5/ s. The static permittivity /spl epsiv//sub s/ and the induced permittivity /spl epsiv//sub /spl infin// of the superlattice estimated by extrapolating the Cole-Cole plot of the dispersion curve of the superlattice to frequencies /spl omega/=0 and /spl omega/=/spl infin/ are 3.80 and 3.57 respectively. The Cole-Cole plot obtained experimentally is found to be broad and fall inside the semicircle of the Cole-Cole plot derived for the Debye relaxation theory, but relatively fits with the semi-empirical Cole-Cole relaxation model with /spl alpha//spl sim/0.68.