First principles investigation of mono-vacancy defective properties of Cr2AlC

For possessing high tolerance to oxidation and radiation damage under irradiation of high fluence heavy ions, nano-laminated Cr2AlC is a better candidate material when used as the functional material in high temperature and nuclear reactors. In this study, the mono-vacancy defect-related properties in Cr2AlC have been investigated by first-principle calculations. The results indicate that the C vacancy could be easily formed due to its low formation energy. It is inferred that the vacancy-mediated migration in Cr2AlC is energetically most favorable for Al vacancy, which can be a proof for elucidating the good oxidation tolerance of Cr2AlC under an oxidizing environment. The conductivity of Cr2A1C will be reduced by the formation of vacancies, while its theoretical Vickers' hardness will be slightly increased. On the other hand, the bulk modulus will be increased through the introduction of mono-vacancy, which will have a negative impact on the shear modulus and the brittle performance of Cr2AlC. In view of the present work, we propose that Cr2AlC can be excellent material for the applications in extreme environments according to our study based on the first-principle calculation.