Table of Contents
Physics Research International
Volume 2011, Article ID 786849, 6 pages
Research Article

Optical Microscopy, X-Ray Diffraction, and Dielectric Permittivity Studies in Binary Mixtures of Nematogens Showing Induced Smectic Phase

1Department of Physics, Karimganj College, Karimganj 788710, India
2Department of Physics, NIT Silchar, Silchar 788010, India

Received 9 April 2011; Accepted 27 May 2011

Academic Editor: Ali Hussain Reshak

Copyright © 2011 Suchismita Datta Sarkar and Basana Choudhury. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The binary mixtures of nematogenic compounds 4-n-pentyl phenyl 4-n′-hexyloxy benzoate (ME6O.5) and 4-cyanophenyl 4-heptyl benzoate (CPHB) show the presence of induced smectic phase. In the present paper we report the phase diagram of the binary system (ME6O.5+CPHB) obtained by polarizing optical microscopy as well as the results of X-ray diffraction and static dielectric permittivity measurements on the system throughout the entire composition range. The observed variation of dielectric anisotropy with molar concentration in the induced smectic phase region is explained by assuming molecular associations in the mixture which is supported by our measurements of layer spacing in the induced smectic phase by X-ray diffraction studies.