压力对B2型金属间化合物YCu性能影响的第一性原理研究  

First-principles Study on Effects of Pressure on Properties of B2 Intermetallic Compound YCu

作　　者：陈鹏飞 米国发[1] 刘晨[1] 霍晓阳[1] 历长云[1] CHEN Pengfei;MI Guofa;LIU Chen;HUO Xiaoyang;LI Changyun(School of Material Science and Engineering,Henan Polytechnic University,Jiaozuo 454000,China)

机构地区：[1]河南理工大学材料科学与工程学院,河南焦作454000

出　　处：《热加工工艺》2022年第18期43-48,共6页Hot Working Technology

摘　　要：采用基于密度泛函理论的第一性原理方法,对B2型金属间化合物YCu在0~50 GPa内不同压力下的晶格参数、弹性性能、声子谱和电子结构进行研究。结果表明:压力对弹性常数影响明显,0~40 GPa内晶体结构力学稳定性好;随着压力的增大,体模量B线性增加;剪切模量G与杨氏模量E先增大,在30 GPa时有明显下降,然后继续增大;在0~20 GPa时,YCu在动力学上能稳定存在;在30~50 GPa时,体系不满足动力学稳定性,会有相变的产生;所有结构在费米能级处态密度的值均不为0,表明体系呈现一定金属性。由分波态密度(PDOS)可知,在费米能级附近的电子态主要由Y原子的p、d轨道贡献,而Cu原子对费米能级附近的电子态基本没有贡献。The first-principles method based on density functional theory was used to study the lattice parameters,elastic properties,phonon spectra and electronic structures of B2 type intermetallic YCu at different pressures from 0 to 50 GPa.The results indicate the effect of pressure on the elastic constants is obvious,and the mechanical stability of the crystal structure is good in the range of 0-40 GPa.With the increase of pressure,the bulk modulus B increases linearly;the shear modulus G and Young’s modulus E increase first,and decrease significantly at 30 GPa,and then continued to increase.From 0 to 20 GPa,YCu can exist stably on the kinetics;from 30 to 50 GPa,the system does not satisfy the kinetic stability,and phase transition occurs.The state density of all structures at the Fermi level is not 0,indicating that the system exhibits a certain degree of metallicity.From the PDOS,the electronic states near the Fermi level are mainly contributed by p and d orbital of the Y atom,while Cu atom does not contribute substantially to the electronic states near Fermi level.

关 键 词：金属间化合物 弹性性能 声子谱 电子结构 第一性原理 

分 类 号：TG113.25[金属学及工艺—物理冶金]