Effect of Fe doping on structural, elastic and electronic properties of B2–ZrCu phase under hydrostatic pressure: A first-principles study

• Published in: Materials chemistry and physics Vol. 272; p. 124978
• Main Authors: Lin, Yujun, Lin, Chaoyu, Cao, Zhenyu, Zhu, Mixun, Zhang, Jingjing, Chen, Anfu, Peng, Ping, Zhang, Yong, Tan, Ming Jen, Fu, Xiaoling
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.11.2021; Elsevier BV
• Subjects: Bonding strength; Brittle materials; Brittleness; Bulk modulus; Charge density; Chemical bonds; Composition; Copper; Diamond pyramid hardness; Doping; Ductile-brittle transition; Ductility; Elastic properties; Equation of state (EOS); Equations of state; First principles; First-principles calculations; Hydrostatic pressure; Inelastic materials; Iron; Phase stability; Poisson's ratio; Substitutes; Topology; Zirconium; ZrCu-based alloys; First-principles calculations; Equation of state (EOS); Elastic properties; ZrCu-based alloys; Hydrostatic pressure
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2021.124978

The effects of Fe doping and applied hydrostatic pressure on structural, mechanical and electronic properties of Zr8Cu8-xFex (x = 0, 1, 2, 3) are investigated via the first-principles calculations. The equation of state (EOS) is established for B2–CuZr crystalline structure. The values are in good agreement with previous experimental results. The phase stability is improved simultaneously by the substitution of Fe for Cu and enhanced hydrostatic pressure for Zr8Cu8-xFex (x = 0, 1, 2, 3). Doping concentration plays an important role in tuning the values of bulk modulus B. However, the values of Vickers hardness HV follows the sequence as: Zr8Cu6Fe2 > Zr8Cu7Fe1 > Zr8Cu5Fe3 > Zr8Cu8 (0–30 GPa). The sequence of B/G, Poisson's ratio ʋ is just opposite to that of HV. It implies a strong correlation between ductility and charge density topology (closely related to bonding character and substitutional atomic sites). Substitution of Fe for Cu tailor the metallic characteristic of Zr–Cu bond into more directional covalent characteristic of Zr–Fe bond, thus make doped Zr8Cu8-xFex (x = 1, 2, 3) harder and more brittle than non-doped Zr8Cu8. The hydrostatic pressure generally enhances the predominant metallic character of Zr8Cu8-xFex (x = 0, 1, 2, 3), thus make all doped and non-doped compositions transit into a more ductile regime. The combined effects of directional bonding and pressurizing thus make Zr8Cu6Fe2 (0 GPa) the most hard and brittle material and Zr8Cu8 (30 GPa) the most ductile material among all compositions. [Display omitted] •High pressure not only stabilizes the structure, but also enhances the ductility of non-doped Zr8Cu8 and doped Zr8Cu8-xFex (x=1, 2, 3).•The electron density topology is closely related to the ductility/brittleness of all compositions.•The equation of state for B2–ZrCu is established. The results are in good agreement with previous experimental measurements.