Numerical simulation studies of the new quaternary MAX phase as future engineering applications: The case study of the Nb2ScAC2 (A = Al, Si) compounds.

Recently, MAX phases have attained considerable technological interest owing to their two inherent properties metallic and ceramic properties. This study extensively examined Nb2ScAC2 MAX phases using DFT, to assess the structural, mechanical, electronic, and Thermal characteristics. Firstly, the stability of these two compounds was confirmed through the formation energy, elastic constants (Cij), and phonon band structure, which confirmed their thermodynamic, mechanical, and dynamical stability. The optimized lattice parameters of these compounds were examined and then utilized to calculate the physical properties of the Nb2ScAC2 compound. Our compounds are brittle due to their Pugh's ratio of less than 1.75. The covalent bonding of the structure revealed by the Poisson ratio is less than 0.25 for the two compounds. The Nb2ScAC2 material is anisotropic, and Nb2ScAlC2 is harder than Nb2ScSiC2.The metallic character of the materials was affirmed by the electronic band structure analysis. Calculated thermal properties such as Debye temperature and minimum and lattice thermal conductivity reveal that both compounds have the potential to enhance their deployment in thermal barrier coating materials. On the other hand, the high melting temperatures indicate that our compounds could potentially be utilized in demanding or severe conditions. Finally, the thermodynamic characteristics, comprising the isochoric heat capacity (Cv) and Debye temperature (Ï´D) were analyzed subjected to high temperatures and pressures. The optical constants such as real and imaginary parts of the dielectric function, refractive index and reflectivity, are investigated. The current study recognizes these two compounds as promising candidates for utilization in modern technologies and diverse industries.

First-principles calculations to investigate physical properties of orthorhombic perovskite YBO3 (B = Ti & Fe) for high energy applications.

Orthorhombic oxide perovskite compounds are very promising materials for the applications of optoelectronics and thermal barrier coating. This work represents a numerical simulation of YBO3 compounds through the first-principles ab initio approach. The electronic and magnetic properties are investigated employing the general gradient approximation (GGA) coupled to the integration of the Hubbard U-term which is the GGA + U. The Ti and Fe-based YBO3 perovskite compounds are found to be actively promising within the ferromagnetic configuration and their lattice parameters are consistent with the previous studies. The calculations of formation energy signify that the compounds YBO3 are stable thermodynamically. The electronic properties are computed and evaluated by the band structure and density of states for both compounds and the results depict that these materials are ferromagnetic half-metallic. Mechanically these compounds are stable, ductile, anisotropic, and hard to scratch. The thermal properties are evaluated for YBO3 (B = Ti and Fe) compounds up to a temperature range of 2000 K. This work can open new opportunities for further exploration in this field.