Critical-like behavior of ionic-related, low-frequency dielectric properties in compressed liquid crystalline 8OCB and its nanocolloid

Abstract

The report presents pressure-related broadband dielectric spectroscopy (BDS) studies in liquid crystalline octyloxycyanbiphenyl and its nanocolloid with BaTiO3 nanoparticles, focused on the low-frequency ionic domain and the impact of pretransitional fluctuations. Hence basic exogenic (pressure) and endogenic (nanoparticles) impacts on dielectric properties are addressed. The innovative derivative-based analysis revealed functional 'critical-like' descriptions of ionic contributions to dielectric permittivity and electric conductivity. The supplementary dielectric constant scan, yielding insight into dipole-diple arrangements, is also presented. Studies cover the puzzling case of complex liquid (SmA) - Solid crystal phase transition, revealing relatively strong critical-like premelting effects, which have hardly been observed for the discontinuous 'melting transition' so far.