DOI: 10.18150/rfkrc9
title: Critical-like behavior of low-frequency dielectric properties in compressed liquid crystalline octyloxycyanobiphenyl (8OCB) and its nanocolloid with paraelectric BaTiO3

description: The results of isothermal, pressure studies of a liquid crystal 8OCB (4-(4´-n-Octyloxyphenyl)benzonitrile) and its nanocolloid doped with 0.5 wt % of paraelectric BaTiO3 nanoparticles (diameter d = 50 nm). Studies were focused on dielectric properties associated with the low-frequency domain of the dielectric spectra and the influence of fluctuations on these properties. The dataset contains:the results of broadband dielectric spectroscopy (BDS) measurements in the frequency range from 1Hz to 10 MHz (carried out using Novocontrol Alpha-A analyzer);polarized light microscopy (POM) photographs (carried out using Studar® Lab Pol microscope, produced by PZO Mikroskopy, and Canon EOS 6D Mark II camera).Both BDS and POM studies were conducted at a constant temperature T = 358 K on increasing pressure (from 0.1 MPa to about 300 MPa). The names of the individual files correspond to the numbering of the figures in the paper: Łoś, J., A. Drozd-Rzoska, and S. J. Rzoska. "Critical-like behavior of low-frequency dielectric properties in compressed liquid crystalline octyloxycyanobiphenyl (8OCB) and its nanocolloid with paraelectric BaTiO3." Journal of Molecular Liquids 377 (2023): 121555. Files included in this collection:fig01 – dielectric spectra - the real and the imaginary parts of the complex dielectric permittivity measured in 8OCB and its nanocolloid doped with 0.5 wt%. BaTiO3 nanoparticles.fig02 – dielectric spectra - the real part of the complex electric conductivity measured in 8OCB and its nanocolloid doped with 0.5 wt%. BaTiO3 nanoparticles.fig03 – the imaginary part of dielectric permittivity as a function of frequency measured in the solid phase (P = 250 MPa) of 8OCB and its nanocolloid doped with 0.5 wt%. BaTiO3 nanoparticles.fig03_inset – the skeletal formula of 8OCB moleculefig04-05 – Pressure changes of the dielectric constant in 8OCB and its nanocolloid, in the isotropic liquid, LC mesophases, and the solid phase.fig06 – the pressure evolution of the real part of dielectric permittivity at selected frequencies measured in 8OCB and its nanocolloid doped with 0.5 wt%. BaTiO3 nanoparticles.fig07-09 – The pressure evolution of the LF contribution to the real part of dielectric permittivity at selected frequencies measured in 8OCB and its nanocolloid doped with 0.5 wt%. BaTiO3 nanoparticles.fig10-12 – The pressure evolution of DC electric conductivity measured in 8OCB and its nanocolloid doped with 0.5 wt%. BaTiO3 nanoparticles.13_a – Polarized light microscopy image of transition from the isotropic liquid into the nematic phase of 8OCB.13_b_20 – Polarized light microscopy image of transition from the isotropic liquid into the nematic phase of 8OCB.13_c – Polarized light microscopy image of the nematic phase phases of 8OCB near the clearing point.13_d_21 – Polarized light microscopy image of the nematic phase of 8OCB 1 MPa above clearing pressure.13_e – Polarized light microscopy image of the nematic phase of 8OCB at a pressure close to the nematic-smectic A phase transition point.13_f_22 – Polarized light microscopy image of the smectic A phase of 8OCB at a pressure near the nematic-smectic A phase transition point.13_g – Polarized light microscopy image of smectic A phase of 8OCB at the middle of the pressure range of the smectic A phase existence.13_h_23 – Polarized light microscopy image of the smectic A phase of 8OCB at a pressure near the crystallization point.13_i – Polarized light microscopy image of the solid and the smectic A phases of 8OCB at crystallization pressure.14_a_15 – Polarized light microscopy image of transition from the isotropic liquid into the nematic phase of 8OCB+BaTiO3 (0.5 wt%) nanocolloid.14_b_16 – Polarized light microscopy image of transition from the isotropic liquid into the nematic phase of 8OCB+BaTiO3 (0.5 wt%) nanocolloid.14_c_17 – Polarized light microscopy image of the nematic phase of 8OCB+BaTiO3 (0.5 wt%) nanocolloid at pressure close to the isotropic-nematic phase transition.14_d– Polarized light microscopy image of the nematic phase of 8OCB+BaTiO3 (0.5 wt%) nanocolloid at a pressure close to the isotropic-nematic phase transition.14_e –Polarized light microscopy image of the nematic phase of 8OCB+BaTiO3 (0.5 wt%) nanocolloid.14_f_18 –Polarized light microscopy image of the nematic to the smectic A phase transition of 8OCB+BaTiO3 (0.5 wt%) nanocolloid.14_g_19 – Polarized light microscopy image of the smectic A phase of 8OCB+BaTiO3 (0.5 wt%) nanocolloid at pressure close smectic A-crystal phase transition.14_h – Polarized light microscopy image of the smectic A phase of 8OCB+BaTiO3 (0.5 wt%) nanocolloid at pressure close smectic A-crystal phase transition.14_i – Polarized light microscopy image of the solid phase of 8OCB+BaTiO3 (0.5 wt%) nanocolloid.