Papers by Author: A.V. Turik

Abstract: Using self-consistent effective-medium theory, we studied the complex elastic compliances of conducting disordered heterogeneous piezoelectric-polymer systems. The considered system is a random mixture of piezoelectric spheroids and polymer ones with the same orientation. The proximate cause of the effective elastic constants frequency dependencies was considered. The nature of the obtained spectra was analyzed.

Abstract: The effective complex piezoelectric and dielectric constants of disordered heterogeneous systems of the type of statistical mixtures with the components in the form of spheroid-shaped particles equally oriented but randomly arranged in space were studied. It has been found for the first time that in such systems there appears a giant piezoelectric enhancement accompanied by a giant relaxation of piezoelectric coefficients and the dielectric permittivity. Piezoelectric and dielectric spectra differ significantly from the Debye ones and are of Davidson-Cole type. The influence of the aspect ratio of spheroids on the effects under consideration was studied. The physical mechanisms responsible for the anomalies in the behavior of piezoelectric coefficients and the dielectric permittivity were considered.

Abstract: A giant enhancement of the static dielectric permittivity and a giant dielectric relaxation in a heterogeneous medium consisting of regularly arranged spheroids distributed in the matrix and described by the Maxwell-Garnett formula were studied. The influence of the inclusions aspect ratio and their concentration is analyzed. The possibility to apply the obtained results to the theoretical consideration of different heterogeneous ferroactive materials is proved. It is shown that observation of the collective dielectric resonance in such media is impossible, and only relaxation processes are the way of obtaining unusual properties of considered materials. Some valuable formulae are derived and discussed.