Mössbauer Investigations of Liquid Crystalline Systems

Abstract

Abstract MöIossbauer spectra of solutions of diacetylferrocene in 4,4′-di-n-hcptyloxyazoxybenzene hcptyloxyazoxybenzene and 4,4′-di-n-octloxyazoxybenzene possessing the nematic and smectic mesophases have been investigated. Gamma-resonance was observed in both phases; its existence in the nematic mesophase can be explained by the preservation of smectic structure fragments -cybotactic groups. The dependence of Mossbauer effect probability and of the asymmetry of quadrupole doublets diacetylferrocene in the oriented 4,4′-di-n-heptyloxyazoxybenzene solutions versus the angle between the applied externad magnetic field and the γ-ray beam were studied for. Under the assumption of' “cone of planes” structure of the oriented system the angle of the slope of heptyloxyazoxybenzene molecules in smectic layers was determined (40 ± 15)°.