摘要
基于密度泛函理论的VASP(Vienna ab-initio simulation package)软件包进行第一性原理计算,研究压力状态下Al_(7)Cu_(2)Fe相的能带和各向异性变化情况.结果表明,在0~50 GPa的压力范围内Al_(7)Cu_(2)Fe相具有金属性,且压力有助于提高能带中原子轨道的扩展性.Al_(7)Cu_(2)Fe相的(100)和(010)晶面的弹性各向异性随着压力升高而增强,而(110)晶面的弹性各向异性随着压力的升高呈波动上升趋势.基于准谐德拜模型,研究Al_(7)Cu_(2)Fe相的体积模量、德拜温度、热容和热膨胀系数随温度和压力的变化情况.结果表明,外加压力和温度对Al_(7)Cu_(2)Fe相热力学性质的影响是相反的.外加压力能有效提升Al_(7)Cu_(2)Fe相的体积模量和德拜温度,而温度升高会导致体积模量和德拜温度降低.Al_(7)Cu_(2)Fe相的热容和热膨胀系数在温度和压力下的变化规律基本一致.
The band structures and elastic anisotropy of Al_(7)Cu_(2)Fe phase under various pressures are studied by using the Vienna ab-initio simulation package(VASP)based on density functional theory.The results show that Al_(7)Cu_(2)Fe phase is still metallic in the pressure range of 0 to 50 GPa and the pressure can improve the expansion of atomic orbital in the energy band.The elasti anisotropy in(100)and(010)planes of Al_(7)Cu_(2)Fe phase enhances with the increase of pressure,while the elasti anisotropy in(110)planes shows a fluctuating upward trend from 0 GPa to 50 GPa.Based on the quasi-harmonic Debye model,the changes of bulk modulus(B),Debye temperature(ΘD),heat capacity(C v and C p)and thermal expansion coefficient(α)of Al_(7)Cu_(2)Fe phase with pressure and temperature are studied.The effects of applied pressure and temperature on thermodynamic properties of the Al_(7)Cu_(2)Fe phase is opposite.The values of B andΘD decrease with temperature and increase with the pressure.In addition,the variation trends of C v,C p andαunder pressure and temperature are basically the same.
作者
唐大富
田晋忠
张永梅
TANG Dafu;TIAN Jinzhong;ZHANG Yongmei(Boiler and Pressure Vessel Inspection Institute of Shanxi Province,Taiyuan 030012,Shanxi Province,P.R.China;School of Materials Science and Engineering,North University of China,Taiyuan 030051,Shanxi Province,P.R.China;School of Science,North University of China,Taiyuan 030051,Shanxi Province,P.R.China)
出处
《深圳大学学报（理工版）》
CAS
CSCD
北大核心
2021年第4期427-432,共6页
Journal of Shenzhen University(Science and Engineering)
基金
山西省高等学校科技创新计划资助项目(2020L0280)
中北大学科学研究基金资助项目(XJJ201909)。
