Universal Journal of Physics and Application Vol. 13(3), pp. 43 - 53
DOI: 10.13189/ujpa.2019.130301
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Investigation of Electronic Structure, Mechanical, Magnetic Properties and Thermal Properties of Co₂CrSi_1-xAl_x Quaternary Heusler Alloys: An Ab-initio Study

I. Asfour ^1,*, Soraya Ababou-Girard ², Didier Sébilleau ^2
1 Department of Material Technology, Faculty of Physics, University of Science and Technology Mohamed-Boudiaf, Algeria
² Department of Nanosciences Materials, Institute of Physics of Rennes, University of Rennes1, France

ABSTRACT

The structural, electronic and elastic properties of full- Heusler alloys Co₂CrZ (Z=Si,Al) and their quaternary compound Co₂CrSi_1-xAl_x, are determined using the full potential linearized augmented plane waves (FP- LAPW) method based on (GGA) the Generalized Gradient Approximation and density functional theory (DFT) implemented in the WIEN2k package. As results, quaternary compound in CuHg₂Ti-type crystal structure are stable. Density of states (DOS) and bands structure show the existence of energies band gaps in their minority-spin channels with half-metallic behavior. The lattice constant of new quaternary alloys Co₂CrSi_1-xAl_x exhibits a small deviation from Vegard's law and a marginal deviation of the bulk modulus from linear concentration. The three independent elastic constants (C₁₁, C₁₂, and C₄₄) are calculated from the direct computation of the stresses generated by small strains. Besides, we report the variation of the elastic constants as a function of pressure as well. From the calculated elastic constants, the mechanical character of Co₂CrSi_1-xAl_x is predicted; elastic constants are calculated to investigate stability criteria and the mechanical nature of the studied materials. The quaternary compound is found to be mechanically anisotropic, ductile and meet the elastic stability criteria. A regular solution model is used to investigate the thermodynamic stability of the alloy which essentially shows a miscibility gap phase by calculating the critical temperatures of the alloys.

KEYWORDS
FP-LAPW Method, Half-metallic, GGA, DOS, Minority-spin, Spintronic

Cite This Paper in IEEE or APA Citation Styles
(a). IEEE Format:
[1] I. Asfour , Soraya Ababou-Girard , Didier Sébilleau , "Investigation of Electronic Structure, Mechanical, Magnetic Properties and Thermal Properties of Co₂CrSi_1-xAl_x Quaternary Heusler Alloys: An Ab-initio Study," Universal Journal of Physics and Application, Vol. 13, No. 3, pp. 43 - 53, 2019. DOI: 10.13189/ujpa.2019.130301.

(b). APA Format:
I. Asfour , Soraya Ababou-Girard , Didier Sébilleau (2019). Investigation of Electronic Structure, Mechanical, Magnetic Properties and Thermal Properties of Co₂CrSi_1-xAl_x Quaternary Heusler Alloys: An Ab-initio Study. Universal Journal of Physics and Application, 13(3), 43 - 53. DOI: 10.13189/ujpa.2019.130301.