DIELECTRIC-PROPERTIES AND DIFFUSION OF FERROELECTRIC PHASE-TRANSITION IN LEAD INDIUM NIOBATE

Temperature dependences of dielectric permittivity and tanδ in PbIn0.5Nb0.5O3 crystals where the degree of compositional order was changed by annealing at 400–I050 °C and subsequent cooling at different rates are determined. In these crystals the diffuse phase transition from paraelectric to ferroelectric phase is accompanied by the tanδ increase. In the vinicity of the transition between para- and antiferroelectric phases there exist no tanδ anomalies. Such anomalies may serve as a criterion allowing to distinguish ferro- and antiferro-electric transitions. The degree of ferroelectric transition diffusion depends on the cooling rate after annealing: the lower the rate, the higher the diffusion. © 1990, Taylor & Francis Group, LLC. All rights reserved.