E.S.R. of vanadyl acetylacetonate dissolved in a liquid crystal at room temperature

Abstract

The E.S.R. spectrum of vanadyl acetylacetonate dissolved in a liquid crystal which is nematic at room temperature has been investigated. The spectrum differs from other E.S.R. studies in liquid crystals with nematic ranges at elevated temperatures in that the molecular tumbling time has slowed enough to produce a ‘glassy’ type spectrum. Previous theories are no longer applicable and a method is discussed for determining the degree of order from the relative intensities of the parallel and perpendicular components of the hyperfine spectrum. The method is supported by the drastic change in intensities upon application of a transverse electric field.