Synthesis of Perovskite-Type Complex Oxide Compound Pb(Zn1/3Nb2/3)O3

By the solid state reaction of the mixture 3PbO+ZnO+Nb2O5 a pyrochlore-type (Pb, Zn)2Nb2O7, was obtained, while perovskite-type A2+(B2+1/3Nb5+2/3)O3 (A2+=Ba, Sr and B2+=Zn, Mg, Co, Ni; A2+=Pb2+ and B2+=Mg, Co, Ni) can be prepared by usual solid state reactions. To obtain a perovskite-type Pb(Zn1/3Nb2/3)O3, a pressure higher than 25 kbars at 800°-1000°C was necessary. Another method to obtain the perovskite form was quenching the molten solution from the temperatures higher than 1200°C. These conditions are considered to favor Zn coordination number to change into 6.