A comparative study on the stability of six Ir/Ir₃X (X = Ti, V, Zr, Nb, Hf, Ta) interfaces by first-principle and AIMD calculations

Interfacial stability is critical for dual-phase Ir/Ir₃X materials used in ultra-high temperature applications. Despite this, this property remains poorly recognized and understood. In the present work, the interfacial energies and the generalized stacking fault energies (GSFE) curves are calculated to investigate the thermodynamic and kinetic stability of the six Ir/Ir₃X interfaces by DFT and AIMD methods. It is found that Ir/Ir₃Ti possesses the lowest interfacial energy at 0 K and 2000 K, as well as the highest unstable stacking fault energy, indicating it is the most stable interface. The comparison shows that the considered interfaces containing IVB elements (Ti, Hf and Zr) are more stable than those containing VB elements (V, Nb and Ta). Furthermore, the analysis reveals that interfacial energy differences in Ir/Ir₃X may contribute to interfacial lattice misfit and charge redistribution at the interface. We aim to provide essential theoretical guidance for the design of novel high-temperature dual-phase Ir-based alloys.