On modeling of grain boundary segregation in aliovalent cation doped ZrO2: Critical factors in site-selective point defect occupancy

Correlation between the bond strain and stabilization of point defects near a symmetric grain boundary in ZrO2 materials is examined to reveal essential factors for grain boundary segregation of dopants and O2- vacancies. Even at dilute dopant concentrations the segregation sites cannot be predicted from bond strain alone. Rather, long-range Coulombic interactions which prevail more in grain interior play a dominant role to determine local modifications at grain boundaries, i.e., enrichment and site-selective occupation of point defects with varying magnitude.