压力对Ni_3Pt电子结构和力学性能的影响:第一性原理研究

Pressure Effects on the Electronic Structure and Mechanical Properties of Ni_3Pt: a First-Principles Study

采用基于第一性原理的平面波赝势方法,研究了压力对γ’-Ni3Pt电子结构和力学性能的影响。本研究在050 GPa压力范围内每隔5 GPa对γ’-Ni3Pt进行一次加压计算。计算结果表明：0 GPa压力下的平衡晶格常数与他人的实验研究和理论计算结果十分一致;不同压力下的总态密度和分波态密度表明化合物表现出金属特性,且随着压力的增大,体系稳定性先增强后减弱;此外,根据Voigt-Reuss-Hill（VRH）法计算了Ni3Pt的体积模量（B）、剪切模量（G）、杨氏模量（E）和泊松比（v）,发现随着压力的增大,Ni3Pt晶体的硬度提高,延性和塑性增强。研究表明,压力对Ni3Pt电子结构和力学性能的影响很大。

By the first-principles plane-wave pseudopotential method based on the density functional theory,the effects of pressure on the electronic structure and mechanical properties of γ’-Ni3Pt were studied.The first-principles calculations have been carried out on γ’-Ni3Pt as a function of pressure from 0 to 50 GPa with a step 5 GPa.The results indicate that the equilibrium lattice parameters under zero pressure are consistent with other experimental and theoretical data.The calculated total density of states and partial density of states under different pressures show that the compound exhibits metallic properties,and the stability of system increases first and then decreases with the increase of pressure.In addition,the bulk modulus（B）,shear modulus（G）,Young’s modulus（E） and Poisson’s ratio（v） of Ni3Pt were calculated by the Voigt-Reuss-Hill method（VRH）.It’s found that the hardness and ductility of crystal are improved as the pressure increases.In short,it’s calculated that the pressure has a marked impact on the electronic structure and mechanical properties of Ni3Pt.