Helical Pitch in Bicomponent Mixtures with Induced Antiferroelectric Phase

The induced antiferroelectric phase in bicomponent mixtures of fluorinated compound C6F13C2H4OPhPhCOOPhCOOC*H(CH3)C6H13 and a member of homologous series of CnH2n+1COO(CH2)3OPhCOOPhPhCOOC*H(CH3)C6H13 (n = 1-7) are observed. In those systems also SmC* α phase was evidenced. The helical pitch was measured and it was found that helical pitch increases with the increase of concentration of fluorinated component in mixture. The pitch of SmC*A phase is longer than for SmC* phase. Additionally the pitch in induced SmC*A phase does not depend on temperature, while in single compounds with SmC*A phase strongly increases.