Electronic structure, mechanical and thermal properties of V-C binary compounds
The electronic structure, mechanical and thermal properties of VC, α-V2C, β-V2C,V4C3, V6C5 and V8C7 are investigated systematically using the CASTEP by the first principles calculation using density functional theory combined with the Debye quasi-harmonic approximation.Formation enthalpy is calculated and used to estimate the stability of the V-C binary compounds.The electronic structures and chemical bonding characteristics are analyzed by the band structures, density of states and Mulliken population analysis.The elastic constants of single crystal, hardness, bulk,shear, Young”s modulus and Poisson”s ratio of polycrystalline crystal are obtained and compared with the experimental results.The anisotropic mechanical properties are discussed using anisotropic index, three-dimensional surface contours and their planar projections on different planes of bulk and Young”s modulus.VC exhibits the largest mechanical modulus because of its strong chemical bonding and α-V2C reveals the weakest elastic anisotropy.The specific heats at constant pressure and volume and the thermal expansion coefficients of the V-C binary compounds versus T from 0-1000 K are calculated and the largest and smallest thermal expansion coefficient attribute to α-V2C and V4C3, respectively.
Ceramic carbides First-principle calculation Elastic properties Thermal properties Hardness
XiaoYu Chong YeHua Jiang Rong Zhou Jing Feng
Faculty of Material Science and Engineering,Kunming University of Science and Technology,Kunming 650 School of Engineering and Applied Science,Harvard University,Cambridge,MA 02138,USA
国内会议
苏州
英文
745-772
2014-10-26（万方平台首次上网日期，不代表论文的发表时间）