A Theoretical Study Of Elastic, Electronic, Optical and Thermodynamic Properties Of AlB2 AND TaB2

TL;DR

This study uses ab initio calculations to analyze the elastic, electronic, optical, and thermodynamic properties of AlB2 and TaB2, confirming their metallic nature and mechanical stability, and exploring temperature and pressure effects.

Contribution

It provides a comprehensive theoretical analysis of AlB2 and TaB2's properties using ab initio methods, including optical and thermodynamic aspects not previously studied.

Findings

AlB2 and TaB2 are mechanically stable.

Both compounds exhibit metallic behavior.

Optical properties like absorption and conductivity align with electronic structure results.

Abstract

Using ab initio method we have studied the structural, elastic, electronic, optical and thermodynamic properties of AlB2 and TaB2. We have used plane wave pseudopotential with generalised gradient approximation as implemented in CASTEP program. The independent elastic constants, bulk modulus, Young's modulus, shear modulus, anisotropic factor, Pugh ratio, etc are calculated. This results show that AlB2 and TaB2 are mechanically stable. We have also calculated the band structure and density of states. Band structure results show that AlB2 and TaB2 show metallic behaviour. In order to understand the electronic properties in a better way we have also calculated dielectric function, refractive index, absorption coefficient, conductivity, loss function and reflectivity. Results of absorption coefficient and conductivity are in good agreement with the band structure results. The effect of temperature and pressure on the bulk modulus, Debye temperature, specific heat and also on the thermal expansion coefficient are derived from the quasi-harmonic Debye model with phononic effect in both cases.The results for the elastic and electronic properties are compared to experimental measurements and with the results obtained in different band-structure calculations, however, no optical data are available for comparison.