In this article, we investigated the effect of Cr substitution in place of Fe on the structural, magnetic and transport properties of Co2FeSi alloy. 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 the 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 upto 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 and are compared wherever possible. All these properties make Co2Fe1−xCrxSi a promising material for spintronics application.
@article{arxiv.1804.05321,
title = {$\mathrm{Co_2Fe_{1-x}Cr_xSi}$ Heusler Alloys : A promising material for spintronics application},
author = {Deepika Rani and Jiban Kangsabanik and K. G. Suresh and N. Patra and D. Bhattacharyya and S. N. Jha and Aftab Alam},
journal= {arXiv preprint arXiv:1804.05321},
year = {2018}
}