Preparation of single-phase Pb(Mg1/3Nb2/3)O3 samples utilizing information from solubility relationships in the Pb–Mg–Nb–citric acid–H2O system

Abstract

The optimum pH for preparing single-phase Pb(Mg_1/3Nb_2/3)O₃(PMN) powder can be estimated from the solubility vs. pH diagrams for the corresponding metal ions in hydroxide, carbonate and citrate media. The homogeneous and stoichiometric citrate PMN precursor could be prepared from the system Pb–Mg–Nb–citric acid–H₂O by adjusting the pH of the solution to 6. Ultrafine (0.05–0.3 µm) and stoichiometric PMN powder could be obtained through the thermal decomposition of the citrate precursor at the relatively low temperature of 900 °C.