Role of electronegativity on the bulk modulus, magnetic moment and band gap of Co2MnAl based Heusler alloys

Sanjeev Kumar Srivastava,Author-Shiv Om Kumar,Vineeta Shukla

doi:10.1016/j.jsamd.2019.02.001

Sanjeev Kumar Srivastava, Author-Shiv Om Kumar + Show 1 more

Open Access

https://doi.org/10.1016/j.jsamd.2019.02.001

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Abstract

Abstract In this paper, we have presented the comparative study of mechanical, electrical and magnetic properties of Co2MnAl1−xZx Heusler alloy with Z = Si, Ge and Ga and x = 0, 0.25, 0.75 and 1 using electronegativity (EN) model. We employed density functional theory for numerical calculations. It is found that Co2MnAl1−xZx with Z = Ga, Ge follow the Vegard's law while Co2MnAl1−xSix does not follow the same trend. Among all composition Co2MnAl.25Si.75 alloy is found to be more compressible. Electronic density distribution depicts the ionic nature of Co2MnAl1−xZx alloy systems. The Co2MnAl1−xZx with Z = Si, Ge possess larger magnetic moment and band gap with respect to Co2MnAl1−xGax system which results from the EN difference, degree of delocalization of valence electron, atomic size and atomic number, respectively.

Highlights

In last few years, Heusler alloys have become the promising material due to major applications in spintronics and memory shape devices [1]
The full Heusler compounds are characterized by the formula X2YZ that crystallize in the L21 structure while half Heusler alloys are referred as XYZ which crystallize in the cb1 structure [2,3]
The electronic density distribution depicts the ionic nature of Co2MnAlÀxZx alloy systems

Summary

Introduction

Heusler alloys have become the promising material due to major applications in spintronics and memory shape devices [1]. In this system, the full Heusler compounds are characterized by the formula X2YZ that crystallize in the L21 structure while half Heusler alloys are referred as XYZ which crystallize in the cb structure [2,3]. The electronic structure of these Heusler alloys are obtained to range from metallic to semiconductor relying on their composition. Full Heusler alloys are popular due to half-metallic nature means these alloys possess 100% spin polarization at the Fermi level. Understanding of electrical, Peer review under responsibility of Vietnam National University, Hanoi

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