Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10629495 | Journal of the European Ceramic Society | 2015 | 9 Pages |
Abstract
The electronic structure, mechanical properties and lattice dynamics of YB4 are investigated using first-principles calculations. The Y-B bonding is ionic-covalent, the Y-Y bonding is metallic, the B-B bonding within B6 octahedron is weak Ï-type covalent and that connecting the octahedra is strong Ï-type covalent. The chemical bonding anisotropy has also been confirmed by lattice dynamic properties, and is reflected by the anisotropic elastic stiffness. The maximum Young's modulus (427Â GPa) is 1.5 times larger than its minimum (285Â GPa). The lowest shear moduli are associated with the [1Â 1Â 0](1Â 0Â 0) and [1Â 1Â 0](1Â 1Â 0) systems. The linear compressibility of a (1.70Â ÃÂ 10â3Â GPa) is larger than that of c (1.47Â ÃÂ 10â3Â GPa). Based on the low c44, c66 and Pugh's ratio G/B, YB4 is predicted as a damage to lerant ceramic. YB4 also has a relatively low Young's modulus (339Â GPa), which ensures it good thermal shock resistance.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
Yanchun Zhou, Huimin Xiang, Zhihai Feng, Zhongping Li,