First-principles calculations of phase transition, elasticity, and   thermodynamic properties for TiZr alloy

doi:10.1016/j.jnucmat.2011.10.039

CORC > 北京大学 > 工学院

	First-principles calculations of phase transition, elasticity, and thermodynamic properties for TiZr alloy
	Wang, Bao-Tian ; Li, Wei-Dong ; Zhang, Ping
刊名	journal of nuclear materials
	2012
关键词	HIGH-PRESSURE OMEGA-PHASE BCC PHASE CRYSTAL-STRUCTURE ZIRCONIUM METAL TITANIUM METAL AB-INITIO ZR DIAGRAM SUPERCONDUCTIVITY
DOI	10.1016/j.jnucmat.2011.10.039
英文摘要	Structural transformation, pressure dependent elasticity behaviors, phonon, and thermodynamic properties of the equiatomic TiZr alloy are investigated by using first-principles density-functional theory. Our calculated lattice parameters and equation of state for alpha and omega phases as well as the phase transition sequence of alpha -> omega -> beta are consistent well with experiments. Elastic constants of alpha and omega phases indicate that they are mechanically stable. For cubic beta phase, however, it is mechanically unstable at zero pressure and the critical pressure for its mechanical stability is predicted to equal to 2.19 GPa. We find that the moduli, elastic sound velocities, and Debye temperature all increase with pressure for three phases of TiZr alloy. The relatively large BIG values illustrate that the TiZr alloy is rather ductile and its ductility is more predominant than that of element Zr, especially in beta phase. Elastic wave velocities and Debye temperature have abrupt increase behaviors upon the alpha -> omega transition at around 10 GPa and exhibit abrupt decrease feature upon the omega -> beta transition at higher pressure. Through Mulliken population analysis, we illustrate that the increase of the d-band occupancy will stabilize the cubic beta phase. Phonon dispersions for three phases of TiZr alloy are firstly presented and the beta phase phonons clearly indicate its dynamically unstable nature under ambient condition. Thermodynamics of Gibbs free energy, entropy, and heat capacity are obtained by quasiharmonic approximation and Debye model. (C) 2011 Elsevier B.V. All rights reserved.; Materials Science, Multidisciplinary; Nuclear Science & Technology; Mining & Mineral Processing; SCI(E); EI; 0; ARTICLE; 1-3; 501-507; 420
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/236969]
专题	工学院
推荐引用方式 GB/T 7714	Wang, Bao-Tian,Li, Wei-Dong,Zhang, Ping. First-principles calculations of phase transition, elasticity, and thermodynamic properties for TiZr alloy[J]. journal of nuclear materials,2012.
APA	Wang, Bao-Tian,Li, Wei-Dong,&Zhang, Ping.(2012).First-principles calculations of phase transition, elasticity, and thermodynamic properties for TiZr alloy.journal of nuclear materials.
MLA	Wang, Bao-Tian,et al."First-principles calculations of phase transition, elasticity, and thermodynamic properties for TiZr alloy".journal of nuclear materials (2012).