Binary mixtures of smectic A1S with abnormal behaviour

Binary mixtures are composed of compounds belonging to the 4'cyanobiphenyl-4-yl 4'-n -alkylbiphenyl-4 carboxylate homologous series and halogenophenyl 4-(trans-4-n-decylcyclohexyl)benzoate (10XPCHB) have been studied. Compounds CBnAB are smectic A₁ for n ≤ 7 and smectic A_d for n ≥ 8; compounds 10XPCHB are smectic A, only. It was found that the S_Ad phase of compounds CBnAB exhibits ideal miscibility with the S_A1 phase of compounds 10XTCHB, and that the S_A1 phases of both compounds show abnormal behaviour. The S_A1 phase of compounds CBnAB is destabilized and the range of the S_A1 phase is enhanced on the side of 10XPCHB. The reasons for this behaviour are discussed.