Understanding the interfacial behavior of ceramic substrates with molten salts is critical for developing high-temperature electrochemical technologies. This study employs neural network potentials to investigate interfacial structure and transport properties between 8 mol% yttria-stabilized zirconia (YSZ) and CaF₂-MgF₂ eutectics containing 10 mol% CaO and 10 mol% SiO₂ at 1773 K. Structural and transport analyses unveiled progressive interfacial mixing, characterized by redistribution of Y 3+ and O 2− from the YSZ toward the molten region and interaction of melt species with the near-surface oxides. Mean square displacement (MSD) and diffusivity results indicate a clear mobility hierarchy (i.e., F − > Mg 2+ ≈ Ca 2+ > O 2− > Y 3+ ≫ Zr 4+ ). Our analysis illustrated an enhanced mobility of Y relative to Zr and sustained oxygen transport near the interface. Our simulations revealed a vacancy-mediated corrosion mechanism driven by coupled inward diffusion of melt species and outward migration and depletion of Y 3+ stabilizer ions from the YSZ. This study suggests pre-saturation of the melt with Y-containing additives may mitigate stabilizer depletion. Our findings provide atomistic insight into the mechanisms of early-stage corrosion initiation at the YSZ/molten fluoride interface. • NNIP-MD were used to model YSZ/CaF₂–MgF₂–10 mol%CaO–10 mol%SiO₂ interfaces. • Y 3+ and O 2− diffuse into the melt, while F − and Ca 2+ and Mg 2+ interact with the YSZ surface. • Vacancy-mediated transport governs coupled diffusion and stabilizer depletion. • Si forms SiO₄ units that localize at the interface and promote reaction-layer formation. • Interfacial mixing leads to structural disorder and surface degradation. • Y 3+ migration into the molten phase initiates interfacial corrosion.
Zhang et al. (Tue,) studied this question.