Megahertz Dielectric Relaxation in the Nematic Phases of 4,4′-di-n-propyloxyazoxybenzene and 4,4′-di-n-pentyloxyazoxybenzene

Abstract

The dielectric properties of the third (3. OAOB) and fifth (5. OAOB) members of the PAA homologous series have been investigated in the frequency range from 0.1 to 12 MHz. Negative dielectric anisotropies have been obtained in the nematic phase of both substances. For the dielectric relaxation processes observed parallel to the nematic director, the relaxation times and activation energies have been estimated and discussed.

Microscopic Description of the Dielectric Experiment of Some Liquid Crystals*

“…The complex dielectric permittivity of the 4,4 0 -di-npropyloxyazoxybenzene (in short 3.OAOB) was measured using a coaxial line setup, rectangular waveguides 8) and a multidecameter. 9) In the nematic phase the samples were oriented by means of a magnetic field. In the case of coaxial line a magnetic field of B ¼ 0:25 T was used.…”