Cation Interdiffusion in Polycrystalline Fluorite-cubic MgO–ZrO2 Solid Solution

Lattice and grain-boundary interdiffusion coefficients were calculated from the concentration distributions as determined for cation interdiffusion in polycrystalline MgO-stabilized zirconias by applying a grain-boundary enhanced diffusion model. Lattice interdiffusion coefficients in the temperature range of 1650–1990 °C were represented by \ ildeD=5.9×10−4exp [−293(kJ/mol)/RT] cm2/s. Magnesium self-diffusion coefficients were calculated from the obtained interdiffusion coefficients and the reported Zr self-diffusion coefficients. The results confirmed that interdiffusion in the fluorite-cubic solid solution is primarily controlled by the diffusivity of the faster cation.