Compositional Change and Compositional Fluctuation in Pb(Zr,Ti)O ₃ Containing Excess PbO

Abstract

Compositional changes which take place during sintering of Pb(Zr,Ti)O 3 (PZT) containing excess PbO were studied. The excess PbO forms a liquid phase during the sintering process. The solubility of the TiO 2 component of PZT in liquid PbO is higher than that of ZrO 2 component. Thus, if an excess PbO exists, the composition of PZT phase shifts towards the Ti‐lean side. A change in the lattice constants due to this compositional change was actually observed. Coexistence of tetragonal and rhombohedral phases, due to a compositional fluctuation caused by excess PbO, was observed near the morphotropic phase boundary. When PZT containing excess PbO was sintered at 1100°C, a compositional fluctuation occurred early in the process and then decreased with sintering time. These phenomena have agreed with a result of computer simulation of dissolution of TiO 2 component in PZT phase into liquid PbO phase.