First principles study of structural, electronic and charge transfer properties of high entropy alloys

¹ Department of Material Science and Metallurgical Engineering, University of Pretoria, South Africa
² Photonics Center, Laser Enabled Manufacturing, CSIR, Pretoria, South Africa
³ Next Generation Enterprises and Institutions, CSIR, Pretoria, South Africa
⁴ Manufacturing Cluster, Advanced Materials Engineering, CSIR, Pretoria, South Africa

^* Corresponding author: Jtau@csir.co.za

Abstract

High entropy alloys (HEAs) with unique structural, electronic and functional properties, have emerged as a promising class of materials for hydrogen storage. However, a fundamental understanding of the role of electronic structure and charge transfer mechanisms prior to hydrogenation is still lacking. This study employed first-principles density functional theory (DFT) to analyse the structural and electronic properties, along with the charge distribution mechanism in HEAs. Important parameters like lattice parameters, unit cell volume, formation energies, density of states, valance charge and charge transfer distribution were calculated to evaluate the performance and behaviour of these materials. The results show that Ti₄V₃CrFe₄Al₄ is the most thermodynamically stable. Although alloying with elements of different atomic radii improves the material’s capacity to absorb hydrogen, structural integrity may be jeopardized. Nb has a strong effect on the electronic structure.