DFT-based study of the structural, optoelectronic, mechanical and magnetic properties of Ti 3 AC 2 (A = P, As, Cd) for coating applications.

The first-principles approach has been used while employing the Perdew-Burke-Ernzerhof exchange-correlation functional of generalized gradient approximation (PBE-GGA) along with the Hubbard parameter to study the structural, optoelectronic, mechanical and magnetic properties of titanium-based MAX materials Ti ₃ AC ₂ (A = P, As, Cd) for the first time. As there is no band gap found between the valence and conduction bands in the considered materials, these compounds belong to the conductor family of materials. A mechanical analysis carried out at pressures of 0 GPa to 20 GPa and the calculated elastic constants C _ij reveal the stability of these materials. Elastic parameters, i.e. , Young's, shear and bulk moduli, anisotropy factor and Poisson's ratio, have been investigated in the framework of the Voigt-Reuss-Hill approximation. The calculated values of relative stiffness are found to be greater than ½ for Ti ₃ PC ₂ and Ti ₃ AsC ₂ , which indicates that these compounds are closer to typical ceramics, which possess low damage tolerance and fracture toughness. Optical parameters, i.e. , dielectric complex function, refractive index, extinction coefficient, absorption coefficient, loss function, conductivity and reflectivity, have also been investigated. These dynamically stable antiferromagnetic materials might have potential applications in advanced electronic and magnetic devices. Their high strength and significant hardness make these materials potential candidates as hard coatings.
Competing Interests: There are no conflicts to declare.
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