First-Principles Calculations on Structure, Elastic and Thermodynamic Properties of Al2X (X=Sc, Y) under Pressure


ÇİFTCİ Y., Colakoglu K., DELİGÖZ E., Bayhan U.

JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY, cilt.28, sa.2, ss.155-163, 2012 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 28 Sayı: 2
  • Basım Tarihi: 2012
  • Dergi Adı: JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.155-163
  • Anahtar Kelimeler: Inter metallic compounds, Ab-initio calculation, Elastic properties, Thermodynamic properties, INITIO MOLECULAR-DYNAMICS, TOTAL-ENERGY CALCULATIONS, WAVE BASIS-SET, AB-INITIO, ELECTRONIC-STRUCTURE, SC ALLOY, INTERMETALLIC COMPOUNDS, THERMAL-EXPANSION, LAVES PHASES, TRANSITION
  • Gazi Üniversitesi Adresli: Evet

Özet

To understand deeply the structural, elastic and thermodynamic characteristics of Al2X (X= Sc, Y) compounds in C15 type (space number 227) Cu2Mg structure, we have performed ab-initio density functional theory within the local density approximation (LDA) and the generalized gradient approximation (GGA). The thermodynamic properties of the considered structures are obtained through the quasi-harmonic Debye model. We have presented the results on the basic physical parameters, such as the lattice constant, bulk modulus, pressure derivative of bulk modulus, second-order elastic constants, Zener anisotropy factor, Poisson's ratio, Young's modulus, and isotropic shear modulus: In order to gain further information, the pressure- and temperature-dependent behaviour of the volume, bulk modulus, thermal expansion coefficient, heat capacity, entropy, Debye temperature and Gruneisen parameter were also evaluated over a pressure range of 0-20 GPa for Al2Sc and 0-17 GPa for Al2Y compound and a wide temperature range of 0-2000 K for both compounds. The obtained results were compared with the other reported values.