Acta Metallurgica Sinica (English Letters) ›› 2011, Vol. 24 ›› Issue (4): 255-270.DOI: 10.11890/1006-7191-114-255

• 研究论文 •    下一篇

Structural, elastic and electronic properties for M2XC (M = Ti and Cr, X = Ga and Al) phases from ab initio calculations

Brahim GHEBOULI1,Ghebouli2,Messaoud FATMI3,FatmiBENKERI Mahfoud4,Mohamed Amine GHEBOULI5   

  1. 1. Laboratoire d’Etudes de Surfaces et Interfaces des Matériaux Solides (LESIMS), Université Ferhat Abbas, Sétif 19000, Algérie.
    2. University of BBA
    3. Laboratoire de Physique et Mécanique des Matériaux Métalliques (LP3M), Département d’Optique et mécanique de Précision, Université Ferhat Abbas, Sétif 19000, Algérie.
    4. TCT department
    5. Département de Physique, Centre Universitaire, Bordj Bou-Arréridj 34000, Algérie.
  • 收稿日期:2010-06-17 修回日期:2010-11-01 出版日期:2011-08-25 发布日期:2011-08-18
  • 通讯作者: Mohamed Amine GHEBOULI

Structural, elastic and electronic properties for M2XC (M=Ti and Cr, X=Ga and Al) phases from ab initio calculations

B. Ghebouli1, M.A. Ghebouli2, M. Fatmi3, N. Bouarissa4, M. Benkerri1,I.A. Ibrahim5
   

  1. 1. Laboratory of Study of Surfaces and Interfaces of Solids Materials, Department of Physics, Faculty of Science, University of Setif, 19000, Algeria
    2. Department of Physics, University Center, Bordj Bou-Arreridj 34000, Algeria
    3. Research Unit on Emerging Materials, Ferhat Abbas University of Setif, 19000, Algeria
    4. Department of Physics, Faculty of Sciences, King Khalid University, Abha, P.O. Box 9004, Arabia Saudia
    5. Central Metallurgical Research and Development Institute, P.O.Box: 87 Helwan 11424, Cairo, Egypt
  • Received:2010-06-17 Revised:2010-11-01 Online:2011-08-25 Published:2011-08-18
  • Contact: Messaoud FATMI

PDF (PC)

935

摘要： We report first-principles study of the structural, elastic and electronic properties of the M2XC phases depending on the type of M transition metal (M are Ti and Cr) and on X (X are Ga and Al). Our calculations are performed using the pseudo-potential plane-wave approach in both the local density and generalized gradient approximations. The elastic constants are calculated using the static finite strain technique. Features such as structural and elastic parameters, Debye temperature, sound velocities and their pressure dependence have been investigated. In agreement with experimental and previous theoretical findings, it is found that the compressibility along a and c axis depends on the valence electron concentration (VEC). Correlations revealing the governing role of the X and M elements on the machinability indices of the material have been examined. The electronic properties have been discussed in terms of chemical bonding showing that bonding is due to Md-Cp and Md-Xp hybridizations. M-C bonds are stiffer than M-X ones and Al-Ti (Cr-C) bonds are stiffer than those corresponding to Ti-C (Al-Cr). It is shown that the stiffness of the M–X and M–C bonds increases with increasing the number of VEC.

Abstract: The first-principles study of the structural, elastic and electronic properties of the M2XC phases depending on the type of M transition metal (M are Ti and Cr) and on X(X are Ga and Al) was reported. The calculations are performed using the pseudo-potential plane-wave approach in both the local density and generalized gradient approximations. The elastic constants are calculated using the static finite strain technique. Features such as structural and elastic parameters, Debye temperature, sound velocities and their pressure dependence have been investigated. In agreement with experimental and previous theoretical findings, it is found that the compressibility along a and c axis depends on the valence electron concentration (VEC). Correlations revealing the governing role of the X and M elements on the machinability indices of the material have been examined. The electronic properties have been discussed in terms of chemical bonding showing that bonding is due to Md-Cp and Md-Xp hybridizations. M-C bonds are stiffer than M-X ones and Al-Ti (Cr-C) bonds are stiffer than those corresponding to Ti-C (Al-Cr). It is shown that the stiffness of the M-X and M-C bonds increases with increasing the number of VEC.

Key words: M2XC phases, ab initio, Pressure effect, Band structures