Specific optical properties of doped ionic lyotropic smectics

Abstract

Ionic metal-organic liquid crystals are calling the growing attention of researches in view of variety of their optical, electro-optical and nonlinear optical properties. The typical for this class of mesogenes are metal alkanoates, the structure of which corresponds to smectic A. Salts of alkanoate cacids being mixed with water at room temperature form ionic lyotropic liquid crystals (ILLC), the mesophase structure of which is analogous to that of a thermotropic smectic A. In this work we investigated absorption, luminescence spectra, electrooptical and nonlinear optical properties of ILLC doped with different ionic polymethine dyes. Obtained spectral and optical characteristics of doped ILLC allowed the holography grating recroding. ELectrical investigation has shown that in ILLC and double electrical layer took place near the electrodes. The charge transfer in this area can be described by the Schottky emission through a thin dielectric layer. The comparison with usual liquid crystals shows that the conductivity thin ILLC is more than by three orders higher. Specific spectral, electrical and optical properites of pure and doped ILLC were explained due to the peculiarties of interionic interaction.