Impact of $BaTiO_3$ nanoparticles on pretransitional effects in liquid crystalline dodecylcyanobiphenyl

Abstract

The pretransitional behavior of dodecylcyanobiphenyl (12CB) (isotropic-smectic-A-solid mesomorphism) with $d = 50$ nm $BaTiO_3$ nanoparticles (NPs) linked the cubic phase was monitored via temperature studies of dielectric constant. Tests were carried out in the isotropic, liquid crystal mesomorphic and solid phases. For each phase transition the same value of the critical exponent $\alpha=0.5$ was obtained, including nanocolloids. All phase transitions show the weakly discontinuous nature. The temperature metric of the discontinuity dT notably decreases when adding nanoparticles. The addition of nanoparticles first decreases the dielectric constant by approx. $50%$ in comparison with pure 12CB, but already for a concentration $x = 0.4%% NPs an increase over $50%$ takes place. It is notable that for the latter concentration unique hallmarks of the pretransitional effect emerge also for the solid-mesophase transition. All thease indicate the important impact of nanoparticles on multimolecular mesoscale fluctuations.