The Effect of Cr Substitution on the Anomalous Hall Effect of Co_3−xCr_xAl (x = 0, 1, 2, 3) Heusler Compounds: An Ab Initio Study

Featured Application: Our theoretical studies report the anomalous and spin Hall conductivities of Co3−xCrxAl Heusler compounds in the L21 crystal structure. Based on density functional theory, we studied the electronic, magnetic, and mechanical properties of Co_3−xCr_xAl (x = 0, 1, 2, 3) Heusler compounds with the generalized gradient approximation (GGA) for the exchange-correlation potential. In this study, we report two principal spin-related phenomena, namely, the anomalous Hall effect and current spin polarization of the Co_3−xCr_xAl Heusler compounds in the L2₁ crystal structure. Heusler compounds, both ideally and inversely ordered, were considered. We found that the calculated magnetic moment of Co_3−xCr_xAl decreased with an increase in the Cr concentration for both ideally and inversely ordered structures, except for Cr₃Al. We also found that the spin polarization for all Co_3−xCr_xAl was larger than 50%, except for Cr₂CoAl in the inverse structure. All the considered Heusler compounds were mechanically stable except for the regular Cr₂CoAl. The Hall current spin polarization was also calculated. We found that Co₂CrAl in the XA structure had the largest spin Hall conductivity of 370 ((Formula presented.)), and the spin polarization of the induced Hall current was high.