Determination of elastic constants of a binary system (7CPB+9.CN) showing nematic, induced smectic A(d) and re-entrant nematic phases

作者：Prasad Akhileshwar; Das Malay Kumar^*

来源：Liquid Crystals, 2014, 41(9): 1261-1268.

DOI：10.1080/02678292.2014.915589

• induced smectic phase
• re-entrant nematic phase
• splay and bend elastic constant

The temperature variation of the splay and bend elastic constants of a binary system exhibiting nematic-induced smectic A(d) and re-entrant nematic phases measured by electric field-induced Freedericksz transition method has been reported. As bend deformation is not permitted in the smectic A phase, bend elastic constant (K-33) could only be determined in the nematic and re-entrant nematic phases. In both the nematic phases, the splay elastic constant has the same order of magnitude and does not show any pretransitional effect. However, in the induced smectic A(d) phase, the value of K-11 is about one to two orders higher than that in the nematic phases. The bend elastic constant shows a strong pretransitional effect near the nematic-smectic and smectic-re-entrant nematic phase transitions. The influence of the presence of the induced smectic phase is observed even in those mixtures which have no induced smectic phases. As the smectic phase is approached, the ratio K-33/K-11 increases rapidly and diverges to infinity.

• 出版日期2014