Structural Order/Disorder Phenomena Investigation in Pb-Containing Complex Perovskites with Relaxor Ferroelectric Properties

This article presents the results of studying the samples, obtained on the base of lead magnoniobate (PMN) and described by the general formula (1 – x)PbMg1/3Nb2/3O3 – xPbMg1/2Nb1/2O2.75, where the value of parameter x varies from 0 to 1 with a step of 0.1. Experimentally, it was shown that all compounds from this series are ferroelectric-relaxors. With an increase in the value of the parameter x, the proportion of nonstoichiometric PMN with an artificially set oxygen deficiency increased. Measurements of the dielectric constant of the synthesized samples and the tangent of the dielectric loss angle showed violation of the Curie-Weiss law, which indicates the diffusion of the phase transition.