An ab initio study on the investigation of structural, electronic, mechanical and lattice dynamical properties of the M(2)AX type MAX phases Sc2AlB0.5C0.5, Sc2AlB0.5N0.5 and Sc2AlC0.5N0.5 compounds

Sürücü G., Erkisi A.

MATERIALS RESEARCH EXPRESS, cilt.4, sa.10, 2017 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 4 Sayı: 10
  • Basım Tarihi: 2017
  • Doi Numarası: 10.1088/2053-1591/aa9282
  • Dergi Adı: MATERIALS RESEARCH EXPRESS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Anahtar Kelimeler: MAX phases, ab initio calculations, elastic constant, electronic band structure, phonon, TEMPERATURE COMBUSTION SYNTHESIS, ELASTIC PROPERTIES, THERMAL-CONDUCTIVITY, OPTICAL-PROPERTIES, CRYSTAL-STRUCTURE, TI2ALC, 1ST-PRINCIPLES, PREDICTIONS, STABILITY, OXIDATION
  • Gazi Üniversitesi Adresli: Hayır

Özet

The hypothetical Sc2AlB0.5C0.5, Sc2AlB0.5N0.5 and Sc2AlC0.5N0.5 compounds are M(2)AX type MAX phases referred to as #211 and have hexagonal crystal structure which conforms to P6(3)/mmc space group. These compounds have been investigated by using generalized gradient approximation in the Density Functional Theory and plane-wave pseudopotential method. After the optimization process of the compounds, their structural, electronic, mechanical, and lattice dynamical properties have been examined in detail. The calculated electronic band structure and the total electronic density of states indicated that all of our compounds have metallic behavior. The estimated elastic constants show that they are stable and have anisotropic character mechanically. Moreover, Sc2AlB0.5C0.5 and Sc2AlB0.5N0.5 are ductile, while Sc2AlC0.5N0.5 is brittle. Also, the obtained phonon dispersion curves indicate that Sc2AlC0.5N0.5 is stable, whereas Sc2AlB0.5C0.5 and Sc2AlB0.5N0.5 compounds are dynamically unstable with imaginary vibrational modes.