Novel Route to Lead‐Based Ferroelectric Compounds via Tetragonal Lead(II) Oxide Intermediates

Single-phase perovskite lead-based ferroelectric powders—Pb(Mg1/3Nb2/3)O3(PMN) or 0.9Pb(Mg1/3Nb2/3)O3–0.1PbTiO3(0.9PMN–0.1PT)—were prepared using Mg(NO3)2, instead of MgO or MgCO3, via a mixed-oxide method and one-step calcination. The reaction proceeded via the formation of 3Pb(NO3)2·7PbO, Pb(OH)2, tetragonal PbO, and then 2PbO–Nb2O5(P2N) for PMN or 3PbO–Nb2O5(P3N) for PMN–PT; a mixture of PMN and Pb2(MgxNb1.33)O5.33+x then formed, followed finally by the formation of single-phase PMN or 0.9PMN–0.1PT. Such prepared powder showed excellent room-temperature dielectric constants—13800 for PMN or 22600 for 0.9PMN–0.1PT—by sintering at a temperature of 900°C for 2 h.