DFT insights into double transition metal M2M’SiC2 MAX Phases: Prospects as thermal barrier coatings

Abstract

The exceptional properties of MAX phases in the quaternary group (M₂M'SiC₂) have garnered significant scientific and technological interest due to their unique combination of metallic and ceramic-like characteristics. To gain deeper insights into the properties of these compounds, researchers have utilized Density Functional Theory (DFT). The computational investigations confirm their robust stability, as evidenced by strong mechanical stability criteria and negative formation energies, indicating thermodynamic favorability. Additionally, the phonon dispersion curves of these materials reveal the absence of imaginary frequencies, aligning with theoretical predictions and confirming their dynamical stability. These compounds are found to be ductile, characterized by a predominantly ionic bonding nature. Moreover, Cr₂VSiC₂ and V₂CrSiC₂ exhibit remarkable thermal properties, including high melting and Debye temperatures, which enhance their potential for high-temperature applications. Electronic structure analysis further reveals that M₂M'SiC₂ compounds with hexagonal symmetry exhibit metallic behavior, making them suitable for applications that demand excellent electrical conductivity alongside mechanical resilience. These findings highlight the potential of M₂M'SiC₂ MAX phases for innovative applications in industries requiring materials that combine strength, thermal stability, and metallic conductivity.