SYNTHESIS AND DIELECTRIC-PROPERTIES OF LEAD MAGNESIUM NIOBATE - A REVIEW

Lead-based relaxors are technologically important materials for multilayer ceramic capacitors and electro-optic devices. Typical of relaxor materials is lead magnesium niobate (PMN), which shows excellent dielectric properties. The commercial production of these materials, however, has suffered owing to the nonreproducibility that arises from evaporation of lead oxide during synthesis. This paper reviews the methods attempted for the fabrication of single-phase PMN. The salient features of these processes, with their chemical reactions, advantages and limitations, are described in the first section of this review. The second part of the article summarizes the factors that influence the dielectric properties. The article concludes with a brief discussion of the promising methods for large-scale production of PMN with acceptable dielectric behaviour.