Effect of atomic ordering on structural, electronic and magnetic properties of Co2Cr0.5Fe0.5Al Heusler alloy

• Published in: Journal of magnetism and magnetic materials 2019-07, Vol.481, p.6-11
• Main Authors: Nehra, Jagdish, Jani, Snehal, Dolia, S.N., Lakshmi, N.
• Format: Article
• Language: English
• Subjects: Half-metallicity; Heusler alloys; Magnetic properties; Mössbauer spectroscopy
• ISSN: 0304-8853; 1873-4766
• DOI: 10.1016/j.jmmm.2019.02.084

•We have shown that the partial substitution of Cr with Fe in Co2CrAl Heusler alloy brings excellent structural ordering while the half metallicity in the parent Co2CrAl is retained in the quaternary Co2Cr0.5Fe0.5Al Heusler alloy.•Experimentally the saturation magnetization and Curie temperature is found to increase with the Fe substitution.•The DC magnetisation measurements show week antiferromagnetic interaction, which is the consequence of the antisite Cr atom confirmed by Mössbauer spectroscopy.•Combination of robust structural atomic stability, Curie temperature and half metallicity makes it a very good potential candidate for spintronics applications. The effect of substitution of Fe in place of Cr on structural, electronic and magnetic properties of quaternary Co2Cr0.5Fe0.5Al Heusler alloy has been investigated. The study of X-ray diffraction (XRD) and Mössbauer spectroscopy of annealed sample have a highly ordered B2-type phase. The parameters extracted from the XRD have been used to analyze half metallicity of B2-phase theoretically. The first principal calculations based on generalized gradient approximation predict half metallic ferromagnetic with an energy gap of 0.319 eV in the minority spin channel around the Fermi level. On substitution of Fe in Co2CrAl, DC magnetization studies show an increase in saturation magnetization (3.02 µB/f.u.) and Curie temperature (910 K) compared to its parent alloy Co2CrAl at room temperature. Structural, electronic and magnetic properties of quaternary Co2Cr0.5Fe0.5Al Heusler alloy show that the half metallicity is retained even on partial substitution of Cr by Fe with predominant B2 ordered structure. Thus Co2Cr0.5Fe0.5Al in B2-phase brings excellent structural ordering, high magnetic moment and Curie temperature while retaining the half-metallicity that is useful for spintronics applications.