DFT prediction of new o-MAX phases: Mo2A2AlC3 (A = Zr, Nb, Ta) for next-generation thermal barrier coatings

The incorporation of o-MAX phases, characterized by out-of-plane atomic arrangements, provides valuable extensions to the MAX phase family, driven by their superior thermomechanical properties, which are suitable for high-temperature applications. In this research, three novel o-MAX phases, Mo2A2AlC3 (A = Zr, Nb, Ta), have been newly explored, and their structural geometry, electronic properties, mechanical behavior, thermodynamic characters, and optical response have been comprehensively investigated employing density functional theory (DFT) for the first time.