Interatomic potentials for cubic zirconia and yttria-stabilized zirconia optimized by genetic algorithm

Abstract

Yttria stabilized zirconia (YSZ) is an important engineering ceramic oxide used for various applications, including solid electrolytes in solid oxide fuel cells due to its high ionic conductivity. Accurate and computationally inexpensive interatomic potentials for cubic ZrO2 and YSZ are required to accommodate the large number of defect configurations originating from high concentrations of Y and oxygen vacancies and to statistically understand their properties in realistic time. In this study, a genetic algorithm has been used to optimize empirical interatomic potential parameters for cubic ZrO2 and 10Y2O3 mol% YSZ using energies, forces acting on atoms, and stresses generated by ab initio calculations as training data. The optimized potentials reproduce the structural, mechanical, and thermal properties as well as the ionic conduction properties more accurately than previously reported empirical interatomic potentials. The developed potentials will be useful for a statistical characterization of YSZ properties, combined with more accurate ab initio calculations.