Jump to main content
Jump to site search

Issue 26, 2015
Previous Article Next Article

Novel compounds in the Zr–O system, their crystal structures and mechanical properties

Author affiliations

Abstract

With the motivation of exploring new high-strength ceramics, ab initio evolutionary simulations are performed to search for all the stable compounds in the Zr–O system. We have found that not only the traditional compound ZrO2, but also the ordered suboxides R[3 with combining macron]-Zr6O, R[3 with combining macron]c-Zr3O, P[3 with combining macron]1m-Zr2O and P[6 with combining macron]2m-ZrO are stable at zero pressure. The crystal structure of semimetallic P[6 with combining macron]2m-ZrO consists of Zr-graphene layers and can be described as an intercalated version of the ω-Zr structure. An interesting massive Dirac cone is found in the three-dimensional (3D) band structure of P[6 with combining macron]2m-ZrO at the Γ-point. The elastic properties, the hardness and the correlation between the mechanical properties of Zr–O compounds and the oxygen content have been systematically investigated. Surprisingly, the hardest zirconium oxide is not ZrO2, but ZrO. Both P[6 with combining macron]2m-ZrO and P[3 with combining macron]1m-Zr2O exhibit relatively high hardness values of 14 GPa and 10 GPa, respectively. The anisotropic Young's modulus E, torsion shear modulus Gt and linear compressibility β have been derived for P[6 with combining macron]2m-ZrO and P[3 with combining macron]1m-Zr2O. Further analyses of the density of states, the band structure and the crystal orbital Hamilton population indicate that the electronic structure of Zr–O compounds is directly related to their mechanical properties. The simultaneous occurrence of the 3D-framework of Zr–O and the strong Zr–Zr bonds in P[6 with combining macron]2m-ZrO explains its high hardness.

Graphical abstract: Novel compounds in the Zr–O system, their crystal structures and mechanical properties

Back to tab navigation

Publication details

The article was received on 17 Apr 2015, accepted on 14 May 2015 and first published on 27 May 2015


Article type: Paper
DOI: 10.1039/C5CP02252E
Author version available: Download Author version (PDF)
Citation: Phys. Chem. Chem. Phys., 2015,17, 17301-17310
  •   Request permissions

    Novel compounds in the Zr–O system, their crystal structures and mechanical properties

    J. Zhang, A. R. Oganov, X. Li, H. Dong and Q. Zeng, Phys. Chem. Chem. Phys., 2015, 17, 17301
    DOI: 10.1039/C5CP02252E

Search articles by author

Spotlight

Advertisements