Electronic Stucture And Optiacal Properties Of Tantalum Aluminium Carbon Ternary Layered Ceramet From First Principles

Tantalum aluminum carbon ternary layered ceramic including Ta2 AlC, Ta3AlC2 and Ta4AlC3, with excellent performance of metal and ceramic,arepotential high-quality ceramic materiasl. In this paper, we employed Materials studio5.5 CASTEP calculation software package based on first-principles of density functional theory to calculate electronic structure and optical properties of Ta2 AlC, Ta3AlC2 and Ta4AlC3 layered ternary ceramic, and the mechanism of optical properties has been researched on the basis of the electronic structure.The band structure and density of states of Ta2 AlC, Ta3AlC2 and Ta4AlC3 have been calculated respectively.According to the result of band structure shows that layered ternary ceramic including Ta2 AlC, Ta3AlC2 and Ta4AlC3 are electrical conductors; The total and partial density of states of Ta2 AlC, Ta3AlC2 and Ta4AlC3 have been studied respectively,it illustrate various atomic electron density have some contributions to the total density of states.We calculated the optical properties of Ta2 AlC, Ta3AlC2 and Ta4AlC3, combined with the electronic structure analysis. The results show that the dielectric peak mainly from electronic transitions between the band corresponding to the calculated density of states, Ta2 AlC peak is formed mainly between Ta d and C p orbital electron transitions; Ta3AlC2 and Ta4AlC3 peaks are formed mainly between Al p and Ta d orbital electron transition;absorption spectrum of layered ternary ceramic Ta2 AlC, Ta3AlC2 and Ta4AlC3 up to maximum in the ultraviolet region, similar to the metal, the coefficient of absorption spectra to 105 orders of magnitude, it can absorb from electromagnetic waves to photons in the ultraviolet region, that there will be no optical band gap, the root cause of this result is generated by the ceramic metal bonding.Ta2AlC, Ta3AlC2 and Ta4AlC3 in the visible region(1.0-4.0 eV), has little effect on the reflectivity spectrum of the photon frequency, indicating that they have similar metallic gray transition metal. In the visible region of the small amplitude changes also shows they are potential temperature control coating material; in the ultraviolet region showed a larger reflectance can be inferred that they are a potential anti-UV coating material, Layered ternary tantalum aluminum carbon ceramic can be applied in thescience and technology field of aerospace and defense; the conductivity and the refractive index of Ta2 AlC, Ta3AlC2 Ta4AlC3 increases to reduced with the energy changes, combined partial density of states, their loss function of the peak is due to Ta d and Al p orbitals electronic transitions.Through the research on the electronic structure and optical properties, indicating Ta2 AlC, Ta3AlC2 and Ta4AlC3 is a potential coating material,and provide a theoretical basis for the Layered ternary ceramictantalum aluminum carbon applications, while there will be some contribution for their other nature studies.