第一性原理研究Pt掺杂NiTi金属间化合物晶体结构与电子结构(英文)

First-principle study of crystal structure and electron structure of Pt doped NiTi intermetallic compound

利用第一性原理研究了Pt掺杂B2结构的NiTi合金的晶体结构与电子结构.研究表明,Pt掺杂比例不高于6.25%时,体系的结构不发生变化,并且点缺陷形成能更低,说明掺杂Pt元素能提高体系的稳定性.而态密度,布局分析以及电荷密度分布的计算进一步表明,Pt原子的d电子成键能力很强,与周围原子剧烈的相互作用,结构更为稳定。通过比较不同取代位点得出Pt更倾向于取代Ni位。

Based on the density functional theory, the effect of Pt doping in 16-atom supercell of NiTi is calculated by using the pseudopotential method. Formation energy, density of states, Milliken population and electron density are obtained. The calculated results indicate that Pt dopant can strengthen the stability of B2- NiTi intermetallic compound with doping concentration less than 6.25 at %. The density of states, Milliken population analysis and the plotted electron density of （110） surface suggest that Pt prefer to substitute Ni atom.