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(Li1/4Fe1/4 W1/2)O-3-added Pb(Mg1/3Nb2/3)O-3 ceramics were investigated, Mixing th e two end-members for 4h only formed a mixture, however, 48h-mixing me chanochemically 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 densifi cation of Pb(Mg1/3Nb2/3)O-3, and caused grains to grow greatly and res ulted in nonuniform microstructure, Regardless of mixing conditions, p ure 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 pyro chlore 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 temper ature dependence of dielectric permittivity, The ceramics fabricated b y the mixture of two end-members possessed a larger apparent diffusive ness of dielectric permittivity than those prepared from the partial s olid-solution, implying that a wider compositional fluctuation likely occurred in the former specimen.