Development of fast formation process for synthesizing submicron lead magnesium niobate perovskite powder

The characteristics of the solid-state reaction for synthesizing ultrafine Pb(Mg1/3Nb2/3)O3 powder using a new percursor, Mg4Nb2O9 have been investigated. Quenching the mixtures of Mg4Nb2O9 with excess PbO at 850–900°C without further soaking rapidly leads to the complete formation of perovskite phase without pyrochlore phase. Some residual MgO exists in samples; however, MgO is completely eliminated by nitric acid, thereby producing monophasic Pb(Mg1/3Nb2/3)O3. This process confirms the feasibility to synthesize Pb(Mg1/3Nb2/3)O3 in a fast reaction route. The addition of excess PbO enhances the formation rate of Pb(Mg1/3Nb2/3)O3, and also decreases the minimum temperature required for preparing pure perovskite phase. The particle size of obtained Pb(Mg1/3Nb2/3)O3 powder is within the range of submicron meter, and increases with the increasing amount of PbO used.