Doping and disorder in the Co$_2$MnAl and Co$_2$MnGa half-metallic Heusler alloys

K. Ozdogan; B. Aktas; E. Sasioglu; I. Galanakis

doi:10.1103/PhysRevB.74.172412

paper

Doping and disorder in the Co $_{2}$ MnAl and Co $_{2}$ MnGa half-metallic Heusler alloys

arXiv:cond-mat/0607652 · doi:10.1103/PhysRevB.74.172412

Abstract

We expand our study on the full-Heusler compounds [I. Galanakis \textit{et al.}, Appl. Phys. Lett. \textbf{89}, 042502 (2006)] to cover also the case of doping and disorder in the case of Co $_{2}$ MnAl and Co $_{2}$ MnGa half-metallic Heusler alloys. These alloys present a region of very small minority density of states instead of a real gap. Electronic structure calculations reveal that doping with Fe and Cr in the case of Co $_{2}$ MnAl retains the half-metallicity contrary to the Co $_{2}$ MnGa compound. Cr impurities present an unusual behavior and the spin moment of the Cr impurity scales almost linearly with the concentration of Cr atoms contrary to the Co $_{2}$ MnZ (Z= Si, Ge, Sn) where it was almost constant. Half-metallicity is no more preserved for both Co $_{2}$ MnAl and Co $_{2}$ MnGa alloys when disorder occurs and there is either excess of Mn or $s p$ atoms.

Doping and disorder in the Co2​MnAl and Co2​MnGa half-metallic Heusler alloys

Abstract

Doping and disorder in the Co $_{2}$ MnAl and Co $_{2}$ MnGa half-metallic Heusler alloys