Electronic structure, mechanical and physical properties of Ag alloyed α - Nb5Si3: First-principles calculations

Authors

Bo Guo
Jiang Xu
Xiao lin Lu
Shuyun Jiang
Paul Munroe
Zong-Han Xie, Edith Cowan UniversityFollow

Document Type

Journal Article

Publication Title

Physica B: Condensed Matter

Publisher

Elsevier BV

School

School of Engineering

RAS ID

31196

Funders

Australian Research Council Discovery Project scheme.

Comments

Guo, B., Xu, J., Lu, X. L., Jiang, S., Munroe, P., & Xie, Z.-H. (2019). Electronic structure, mechanical and physical properties of Ag alloyed α-Nb5Si3: First-principles calculations. Physica B: Condensed Matter, 564, 80-90. Available here

Abstract

The effect of Ag additions on the structural, mechanical and thermodynamic properties of α-Nb₅Si₃ is systematically investigated using the first-principles calculations based on density functional theory. The calculated formation enthalpies show that when Nb atoms in α-Nb₅Si₃ are replaced by one and two Ag atoms, Ag atoms prefer Nb^4c sites rather than Nb^16l sites. With increasing concentration of Ag atoms, the elastic moduli and theoretical Vickers hardness of the α-(Nb_1-xAg_x)₅Si₃ compounds decrease, while they become more ductile. Ag additions slightly raise the mechanical anisotropies of α-(Nb_1-xAg_x)₅Si₃ compounds and increases the linear thermal expansion coefficients of the α-(Nb_1-xAg_x)₅Si₃ compounds along the c and a axes, with a decrease in the α_c/α_a ratios. Finally, the anisotropy of acoustic velocities and Debye temperatures for the α-(Nb_1-xAg_x)₅Si₃ compounds were also calculated.

DOI

10.1016/j.physb.2019.04.013

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