Investigation of the Perovskite Phase, Morphology and Dielectric Properties of Lead Magnesium Niobate

The perovskite relaxor ferroelectric lead magnesium niobate Pb(Mg1/3Nb2/3)O-3 is an technologically important material because of its excellent dielectric properties and also large electrostrictive strains. It is not easy to prepare single phase Lead magnesium Niobate because of formation of pyrochlore phase during the reactions. In the present study the Lead Magnesium Niobate was synthesized by two-step solid state reaction method with multiple heat treatments. Double sintering was carried out at 1100 degrees C in first step and 1150 degrees C in second step with intermittent cooling and crushing for reducing pyrochlore phase. XRD data of calcined and sintered Lead Magnesium Niobate confirmed the cubic perovskite structure with reduced pyrochlore phase. The SEM images show the formation of dense grains and the dielectric study shows the frequency dependent nature of dielectric constant, Loss Tangent and Dielectric Conductivity.