ISSN:2321-6212
Deepika Rani, Jiban Kangsabanik, K G Suresh, Aftab Alam, N Patra, D Bhattacharyya2 and S N Jha
Indian Institute of Technology Bombay, India Bhabha Atomic Research Centre, India
Posters & Accepted Abstracts: Res. Rev. J Mat. Sci
The effect of Cr substitution in place of Fe on the structural, electronic, magnetic and transport properties of the Co2FeSi alloy is studied. A comprehensive structural analysis is done using X-ray diffraction (XRD) and extended X-ray absorption fine structure (EXAFS) spectroscopy. Quaternary Heusler compounds Co2Fe1-xCrxSi with Cr content (x = 0.1, 0.3, 0.5) were found to crystallize in cubic structure. The synchrotron-based EXAFS studies reveal that the anti-site disorder increases with the increase in Cr concentration. The saturation magnetization values in all the alloys are found to be less than those expected from the Slater-Pauling rule, which may be due to some inherent disorder. A detailed resistivity analysis in the temperature range of 5-300 K is done, taking into account different scattering mechanisms. The residual resistivity ratio is found to decrease with increasing Cr concentration. A disorder induced resistivity minimum due to weak localization effect is seen for x=0.5. The resistivity measurements also indicate that the half-metallic character survives up to 100 K for x=0.1, whereas the alloys with x=0.3 and 0.5 show signature of half-metallic nature even at higher temperatures. First-principles calculation done with a more robust exchange-correlation functional (namely HSE-06) confirms the half-metallicity in the entire concentration range. Theoretically simulated band gap and magnetic moments compliment the experimental findings. All these properties make Co2Fe1-xCrxSi a promising material for spintronics.
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