中国物理B ›› 2017, Vol. 26 ›› Issue (3): 33102-033102.doi: 10.1088/1674-1056/26/3/033102

• ATOMIC AND MOLECULAR PHYSICS • 上一篇    下一篇

Comparative study of Mo2Ga2C with superconducting MAX phase Mo2GaC: First-principles calculations

M A Ali, M R Khatun, N Jahan, M M Hossain   

  1. 1 Department of Physics, Chittagong University of Engineering and Technology, Chittagong 4349, Bangladesh;
    2 Department of Physics, University of Rajshahi, Rajshahi 6205, Bangladesh
  • 收稿日期:2016-09-25 修回日期:2016-12-21 出版日期:2017-03-05 发布日期:2017-03-05
  • 通讯作者: M A Ali E-mail:ashrafphy31@cuet.ac.bd

Comparative study of Mo2Ga2C with superconducting MAX phase Mo2GaC: First-principles calculations

M A Ali1, M R Khatun2, N Jahan1, M M Hossain1   

  1. 1 Department of Physics, Chittagong University of Engineering and Technology, Chittagong 4349, Bangladesh;
    2 Department of Physics, University of Rajshahi, Rajshahi 6205, Bangladesh
  • Received:2016-09-25 Revised:2016-12-21 Online:2017-03-05 Published:2017-03-05
  • Contact: M A Ali E-mail:ashrafphy31@cuet.ac.bd

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摘要： The structural, electronic, optical and thermodynamic properties of Mo2Ga2C are investigated using density functional theory (DFT) within the generalized gradient approximation (GGA). The optimized crystal structure is obtained and the lattice parameters are compared with available experimental data. The electronic density of states (DOS) is calculated and analyzed. The metallic behavior for the compound is confirmed and the value of DOS at Fermi level is 4.2 states per unit cell per eV. Technologically important optical parameters (e.g., dielectric function, refractive index, absorption coefficient, photo conductivity, reflectivity, and loss function) are calculated for the first time. The study of dielectric constant (ε1) indicates the Drude-like behavior. The absorption and conductivity spectra suggest that the compound is metallic. The reflectance spectrum shows that this compound has the potential to be used as a solar reflector. The thermodynamic properties such as the temperature and pressure dependent bulk modulus, Debye temperature, specific heats, and thermal expansion coefficient of Mo2Ga2C MAX phase are derived from the quasi-harmonic Debye model with phononic effect also for the first time. Analysis of Tc expression using available parameter values (DOS, Debye temperature, atomic mass, etc.) suggests that the compound is less likely to be superconductor.

关键词: first-principles calculations, density of states (DOS), optical properties, thermodynamic properties

Abstract: The structural, electronic, optical and thermodynamic properties of Mo2Ga2C are investigated using density functional theory (DFT) within the generalized gradient approximation (GGA). The optimized crystal structure is obtained and the lattice parameters are compared with available experimental data. The electronic density of states (DOS) is calculated and analyzed. The metallic behavior for the compound is confirmed and the value of DOS at Fermi level is 4.2 states per unit cell per eV. Technologically important optical parameters (e.g., dielectric function, refractive index, absorption coefficient, photo conductivity, reflectivity, and loss function) are calculated for the first time. The study of dielectric constant (ε1) indicates the Drude-like behavior. The absorption and conductivity spectra suggest that the compound is metallic. The reflectance spectrum shows that this compound has the potential to be used as a solar reflector. The thermodynamic properties such as the temperature and pressure dependent bulk modulus, Debye temperature, specific heats, and thermal expansion coefficient of Mo2Ga2C MAX phase are derived from the quasi-harmonic Debye model with phononic effect also for the first time. Analysis of Tc expression using available parameter values (DOS, Debye temperature, atomic mass, etc.) suggests that the compound is less likely to be superconductor.

Key words: first-principles calculations, density of states (DOS), optical properties, thermodynamic properties

中图分类号:  (Ab initio calculations)

  • 31.15.A-
71.15.Mb (Density functional theory, local density approximation, gradient and other corrections) 71.20.-b (Electron density of states and band structure of crystalline solids) 78.20.Ci (Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity))