Analysis of Phase Stability in Cubic Zirconia Solid Solutions by First Principle Molecular Orbital Method
Akihide KUWABARA, Yuichi IKUHARA and Taketo SAKUMA
Abstract:The electronic structure of various kinds of c-ZrO2 solid solutions is calculated by a first principles molecular orbital method. It is foundthat the calculated partial density of states agrees well with the ELNES obtained from ZrO2-8mol%Y2O3. From the calculation for ZrO2-R2O3 syste in which the effect of stabilization on c-ZrO2 is high, the addition of R2O3 was found to remarkably decrease the repulsive Coulomb force between neighboring oxygen ions. In contrast, the addition of TiO2, which has no effect to stabilize c-ZrO2, increases the repulsive interaction between oxygen ions. It was concluded that the instability of c-ZrO2 solid solution depends on the repulsive interaction between neighboring oxygen ions. Key Words:Zirconia, Phase stability, Electronic structure, First principle molecular orbital method, Oxygen vacancy