Dielectric relaxation studies on two systems exhibiting the induced smectic A phase

Abstract

Recently we reported some physical studies (layer spacings using X-ray scattering, low frequency dielectric constants) on two systems exhibiting a maximum (indicating an induced smectic A) as well as a minimum in the A-N transition boundary. In this paper we report measurements of the dielectric relaxation of b.epsi|| (up to 13 MHz) for a few compositions of the two systems. The activation energy in the A phase of the mixtures corresponding to the maximum in the A-N boundary is higher than that of the pure polar component. The results are discussed in relation to the molecular interactions giving rise to the induced smectic A phase.