A macroscopic theory for the dielectric properties of lead magnesium niobate

Abstract

Lead magnesium niobate (Pb3MgNb2O9) is a cubic perovskite-type crystal which shows strong relaxation behaviour in the dielectric properties. Based on recent electron diffraction studies which show ordering of the Mg and Nb ions in this structure, and suggest a lamellar superlattice 'domain' structure, a particularly simple model is proposed to account for the electrical behavior. Based on this model a comparison is made with dielectric, structural, and electro-optic properties.