Layer thinning transition in an achiral four-ring hockey stick shaped liquid crystal

Abstract

Depolarized reflected light microscopy and high resolution optical reflectivity measurements have been conducted on free-standing films of an achiral four-ring hockey stick shaped liquid crystal exhibiting SmA-B2–SmX* transition sequence. A layer thinning transition above the bulk isotropic-SmA phase transition has been observed. This behaviour was highly irreproducible, indicating an irregular layer thinning transition. From optical reflectivity data, both thickness of the free-standing films and the smectic interlayer spacing were determined. This is the first report of the layer thinning transition in a hockey stick shaped liquid crystal.

Keywords:

• free-standing film
• thinning transition
• hockey stick shaped liquid crystal
• optical reflectivity
• intercalated smectic A phase

Acknowledgements

M.K. Paul, a BOYSCAST fellow, thanks the Department of Science and Technology (DST), New Delhi for his fellowship. This study was supported in part by Fast Track Project (DST) Grant no. SR/FTP/CS-43/2006 and National Science Foundation, Solid State Chemistry Program under Grant no. 0605760. Financial assistance provided by DST, DAE and UGC is gratefully acknowledged.