Thermodynamic prediction of the nonstoichiometric phase Zr1-zCezO2-x in the ZrO2-CeO1.5-CeO2 system

A thermodynamic estimation of the ZrO2-CeO2 and ZrO2-CeO1.5 systems, as well as the cubic phase in the CeO1.5-CeO2 system has been developed and the complex relation between the nonstoichiometry, y, in CezO2-y and the oxygen partial pressure at different temperatures is evaluated. The behavior of the nonstoichiometry phase Zr1-zCezO2-x is described based on the thermodynamic estimation in the ZrO2-CeO2, CeO1.5-CeO2 and ZrO2-CeO1.5 systems. Additionally, the interdependence among miscellaneous factors, which can be used to describe the change in oxidation states of cerium such as the oxygen partial pressure, the CeO1.5 fraction in CeO1.5-CeO2 in the quasi-ternary system, the nonstoichiometry y and the difference between the activity of CeO2 and CeO1.5 are predicted. The calculated results are found to be very useful to explain the influence of pressureless sintering at different O-2 partial pressures on the mechanical properties of CeO2-stabilised ZrO2 ceramics (C) 2002 Published by Elsevier Science Ltd.