摘要
采用基于密度泛函理论(DFT)的第一性原理平面波超软赝势方法,计算了Nb元素掺杂对B2构型NiTi金属间化合物电子结构的影响.点缺陷生成能的计算结果表明,Nb原子掺杂后,NiTi中产生Ni原子和Ti原子空位和反位点缺陷所需要的能量均明显升高;态密度计算结果表明,Nb原子掺杂后与临近原子发生了明显的s-s,p-p和d-d电子相互作用,增加了与临近原子之间的电荷密度,有利于Nb与合金原子的成键.这些由Nb掺杂所导致的NiTi电子结构和键合特征的变化均有利于促进Nb与合金原子的相互作用,在一定程度上束缚了合金原子的迁移,有利于提高NiTi合金的抗氧化性能.
The electronic structure of pure and Nb doped B2 NiTi have been calculated with the first-principle ultrasoft pseudopotential approach of the plane wave based on the density functional theory aiming at examining the effect of Nb on the electronic structure and bonding characteristic of NiTi. The point defect formation energy calculation results show that the introduction of Nb largely enhances the energy required to form the vacancies and anti-sites of both Ni and Ti sublattice. Furthermore, the calculation results on the partial density of states （PDOS） suggest that the addition of Nb increase the s-s, p-p and d-d electronic interactions between Nb and neighboring Ni and Ti atoms. The electron density of NiTi was also increased with the introduction of Nb. All these Nb-inuced results on electronic structure and bonding characteristic may hamper the hop of Ni and Ti atoms, which may facilitate to improve of oxidation resistance of NiTi intermetallic compound in the experimental findings.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2010年第1期515-520,共6页
Acta Physica Sinica
基金
国家自然科学基金(批准号:50801003)
高等学校博士学科点专项科研基金(批准号:200800061041)资助的课题~~
关键词
NiTi金属间化合物
点缺陷
电子结构
第一性原理计算
NiTi intermetallic compound, point defect, electronic structure, first-principles calculations
