Phase Equilibrium in the System PbO‐TiO₂–ZrO₂

Abstract

Phase equilibrium relations in the system PbO-TiOz-ZrOz were studied by quenching in the range where the PbO content is 50 mole yo and more. Isotherms were examined at llOOo, 1200°, and 13OO0C and tie lines were determined between the liquid and solid solution in equilibrium. The incongruent melting point of PbZr03 was 157OOC and the equilibrium between liquid, PbO-type solid, and PbZrOa is peritectic. Pb(Zr,Ti)Ol solid solutions containing more than 14 mole yo PbZrOa decomposed to liquid, ZrOz, and Pb(Zr,Ti)Oa and the decomposition temperature rises from 1340° to 157OOC with increasing PbZrO, content. The system PbTi03-PbZr03 should not b e treated as a binary, but as a section of the ternary system.

Thermodynamic Assessment of the PZT System

“…11a and b. According to the present work, the solidification sequence in the PbO-TiO 2 -ZrO 2 system is in agreement with the schematically proposed polythermal projection by Fushimi and Ikeda,18 where the solubility surface for zirconia dominates in the system. The calculated invariant reactions Table 9 are consistent with those estimated in literature.…”

“…10a, b and c are compared with the experimentally determined ones. 18 Isothermal lines are close and almost parallel to the PbO-TiO 2 side. At lower temperatures, the solubility of the ZrO 2 in the liquid phase increases with increasing PbZrO 3 content Figs.…”

“…Such trend is consistent with the results of Fushimi and Ikeda. 18 The calculated projection of the monovariant liquidus lines is shown in Figs. 11a and b.…”

“…The calculated invariant reactions Table 9 are consistent with those estimated in literature. 18 5. Summary Thermodynamic properties of the ternary PbO-ZrO 2 -TiO 2 system are analyzed by means of the CALPHAD method.…”

Effect of manganese doping on the size effect of lead zirconate titanate thin films and the extrinsic nature of ‘dead layers’

“…39 The perovskite structure of PZT is believed to tolerate only 2%-3% Pb deficiency while the pyrochlore (or fluorite) phase is expected to bear a very wide range of Pb excess or deficiency. 40,41 [Fact I; Note that the pyrochlore structure is intimately related to the defective fluorite phase. It is a superstructure of the ideal fluorite structure, AO 2 and has ε <100 and ~50 for the Pt(Au)/PZT/Pt(Au) structure and probably for Au(Pt)/BST/Au(Pt) as well.…”