Alloying effects and site occupancies of Re in the C14 Cr-based Laves phases: a first-principles study

ABSTRACT

First-principles calculations based upon the density functional theory have been carried out to investigate the alloying effects and site occupancies of Re in the C14 XCr₂ (X = Nb, Ta, Ti, Zr, Hf) Laves phases. The calculated results indicate that Re tends to facilitate and participate in the formation of the Laves phases, generating X₈Cr₁₅Re accordingly. The partial density of states and charge density difference were analysed to reflect the bonding characteristics. For X₈Cr₁₅Re, the bonding between the doped Re and its nearest neighbour Cr atoms all show covalent characteristics, which contribute to the phase stability. The substitution of Re on X sites is energetically unfavourable due to the weak bonding between Re and its nearest neighbour X atoms.

KEYWORDS:

• First principles
• Laves phase
• stability
• site occupancy
• bonding characteristics

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 51771102]; [grant number 51271097]; [grant number 51471098].