Direct Determination of the Anisotropy of the Magnetic Susceptibility in Smectic Liquid Crystals

Abstract

A sample of an aligned smectic liquid crystal, suspended in a magnetic field, can be excited to oscillations. Measurement of the oscillation period allows a direct determination of the anisotropy of the magnetic susceptibility. Liquid crystals exhibiting the phase sequence isotropicnematic- smectic A can be aligned very well and precise y.A values can be determined. A direct transformation from the isotropic to the smectic phase or phase transitions between smectic phases can cause an incomplete alignment of the liquid crystal and worse results.