First-principles pair potentials across the metal-ceramic interface

Systematic approaches are presented to invert the first-principle binding energy to obtain the pair potentials across the metal/ceramic interfaces. The conformation characteristics of two virtual interface models suitable for the inversion are summarized: (1) the positions of one kind of ceramic ions stay unchanged, but those of the other change; or, (2) there is no change in the relative positions of the ceramic ions to the metal atoms but the positions of two kinds of ceramic ions are all exchanged each other. As an example, we derive the pair potentials of Ni - Zr⁴⁺ and Ni - O^2- across the Ni/ZrO₂ interface with this method, which exhibit comparable accuracy to the first-principle results. This provides direct evidence that the interfacial potentials obtained from this method can reasonably describe the general features of bondings across the metal-ceramic interface. The limitation of this method is also discussed.