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

Document Type

Journal Article

Publication Title

Physica B: Condensed Matter


Elsevier B.V.


School of Engineering


Australian Research Council Discovery Project scheme.


Originally published as: 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. Original publication available here


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 Nb4c sites rather than Nb16l sites. With increasing concentration of Ag atoms, the elastic moduli and theoretical Vickers hardness of the α-(Nb1-xAgx)5Si3 compounds decrease, while they become more ductile. Ag additions slightly raise the mechanical anisotropies of α-(Nb1-xAgx)5Si3 compounds and increases the linear thermal expansion coefficients of the α-(Nb1-xAgx)5Si3 compounds along the c and a axes, with a decrease in the αca ratios. Finally, the anisotropy of acoustic velocities and Debye temperatures for the α-(Nb1-xAgx)5Si3 compounds were also calculated.