Synthesis and characterization of Pb(Fe2/3W1/3)O3 ceramics obtained by two preparation methods

Lead iron tungstate (Pb(Fe23W13)O3) is difficult to sinter as a single phase perovskite ceramic. Side reactions lead to undesirable second phases damaging the dielectric properties of the sintered material. Understanding these reaction routes is necessary to eliminate them and to improve on the properties of these ceramics. Lead iron tungstate ceramics were sintered from powders prepared by reaction of mixtures of the three oxides, or by reaction of prereacted iron oxide and tungsten oxide with lead oxide, in an attempt to control the formation of the perovskite phase. The reaction sequences, different in both cases, lead to a higher yield of the perovskite phase when the prereacted powders were used, avoiding therefore the presence of undesirable phases. The microstructures and dielectric properties of the sintered ceramics obtained by both methodologies are reported and compared. The prereacted intermediate phase method leads to a more ordered perovskite structure with better dielectric characteristics.