Phase diagram, density and optical studies on binary mixture of a cyanobiphenyl (110CB) and a benzoate ester (ME6.O5) showing enhanced smectic phase

Binary mixture of undecyloxy cyanobiphenyl (11OCB) and 4-n-pentyl phenyl-4- n'-hexyloxy benzoate (ME6.05) shows enhanced smectic A phase, where 11OCB h as smectic, A and ME 6.05 has nematic phases. We report here the phase diag ram, refractive indices, densities and orientational order parameters of di fferent binary mixtures of 11OCB + ME6.05 throughout the entire composition range. At a reduced temperature, density values increases with mole fracti on (x) of 11OCB up to x = 0.25 and then decreases continuously having a min imum near x = 0.8. The birefringence and <P-2> values follow the same trend showing a maximum near x = 0.4 and a minimum near x = 0.8.