摘要
通过基于密度泛函理论的第一性原理计算方法,研究了Pt-M(M=Fe,Co,Ni)各金属间化合物的结构、能量、电子结构和弹性性质。首先对Pt-M(M=Fe,Co,Ni)金属间化合物进行几何优化,对其能带结构、总态密度、分态密度、键合特征和弹性性质进行研究,并计算各金属间化合物的结合能与生成焓。计算所得晶格参数与实验值和文献计算值吻合。PtFe_3的生成焓最小,结合能最大,说明PtFe_3较其他合金相更稳定、键合力更强。通过对Pt-M(M=Fe,Co,Ni)的能带结构和电子态密度进行计算,分析了其结构稳定性的物理本质。PtFe_3-t中Pt-Fe和Fe-Fe键相比其他合金相键长较短且电荷密度较高,说明PtFe_3-t中Pt-Fe和Fe-Fe键的键能比其他合金相大,所以PtFe_3-t合金相的结构稳定性最好。对Pt-M(M=Fe,Co,Ni)弹性性质的研究表明PtFe_3为脆性相,PtFe、Pt3Fe、PtCo、Pt_3Co、PtNi和PtNi3为延性相,其中Pt_3Co的塑性最好,PtFe_3-t有较高的弹性模量,其原子间结合力相对较强,材料的强度较大。
Phase structures,energies,electronic structures and elastic properties of the Pt-M（M=Fe,Co,Ni）intermetallic compounds were investigated by means of first-principles calculations from CASTEP program based on the density functional theory.Crystal structures of Pt-M（M=Fe,Co,Ni）intermetallic compounds were firstly optimized and then the band structure,total and partial density of states,bonding characteristics and elastic properties of these compounds were analyzed,the cohesive energies and formation enthalpies of these phases are also calculated.The calculated lattice parameters coincided well with the experimental and literature values.According to the calculation results,PtFe_3 has the minimum formation enthalpies and the maximum cohesive energies compared to other alloy phases,indicating that PtFe_3 has the most stable structure and strongest bonding energy.The band structures and density of states of Pt-M（M=Fe,Co,Ni）intermetallic compounds were calculated to analyze the physical essence of their structural stability and electronic properties.It should be noted that the calculated bond length of Pt-Fe and Fe-Fe in PtFe_3-t is shorter than another phases,which illustrated the relatively high stability of PtFe_3-t.The charge density provides a measure of the bond strength,so that PtFe_3-t have stronger bond energy than another intermetallic compounds.The calculated elastic properties of Pt-M（M=Fe,Co,Ni）intermetallic compounds suggested the brittleness of PtFe_3 and the ductility of PtFe,Pt3 Fe,PtCo,Pt_3Co,PtNi and PtNi3,among which Pt_3Co is the most ductile.The calculated elasticity modulus of PtFe_3 is the highest,so the atomic binding forces of PtFe_3 is relatively strong,and thereby significantly strengthening the PtFe_3-t.
作者
胡洁琼
谢明
陈永泰
陈松
张吉明
王塞北
HU Jieqiong;XIE Ming;CHEN Yongtai;CHEN Song;ZHANG Jiming;WANG Saibei(School of Materials Science and Engineering,Kunming University of Science and Technology,Kunming 650093;Kunming Institute of Precious Metals,Kunming 650106)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2018年第14期2467-2474,共8页
Materials Reports
基金
国家自然科学基金(U1602275
U1602271
U1302272
51267007
51461023)
云南省院所技术开发专项项目(2013DC016)
云南省稀贵金属材料协同创新基金(2014XT02)
