Role of the addition of Pb(Li1/4Fe1/4W1/2)O-3 in the low-temperature sintering and dielectric characteristics ofph (Mg1/3Nb2/3)O-3 ceramics

The sintering behavior and dielectric characteristics of Pb(Li1/4Fe1/4W1/2)O-3-added Pb(Mg1/3Nb2/3)O-3 ceramics were investigated, Mixing the two end-members for 4h only formed a mixture, however, 48h-mixing mechanochemically induced the reactants to form partial perovskite solid-solutions. In the mixture specimen, the melt of Pb(Li1/4Fe1/4W1/2)O-3 acted as a reactive liquid phase to substantially enhance the densification of Pb(Mg1/3Nb2/3)O-3, and caused grains to grow greatly and resulted in nonuniform microstructure, Regardless of mixing conditions, pure perovskite solid-solutions were formulated at 1000 degrees C when the content of Pb(Li1/4Fe1/4W1/2)O-3 was less than 10 mass%, whereas, adding excess Pb(Li1/4Fe1/4W1/2)O-3 unfavorably caused polyhedral pyrochlore phase to form in the matrix, The addition of Pb(Li1/4Fe1/4W1/2)O-3 decreased the broad maximum of dielectric permittivity of sintered specimens; nevertheless, this addition markedly suppressed the temperature dependence of dielectric permittivity, The ceramics fabricated by the mixture of two end-members possessed a larger apparent diffusiveness of dielectric permittivity than those prepared from the partial solid-solution, implying that a wider compositional fluctuation likely occurred in the former specimen.