Effect of doping and disorder on the half-metallicity of full Heusler alloy

Department of Material Science, University of Patras, Rhion, West Greece, Greece
Applied Physics Letters (Impact Factor: 3.3). 03/2006; 89(4). DOI: 10.1063/1.2235913
Source: arXiv


Heusler alloys containing Co and Mn are amongst the most heavily studied half-metallic ferromagnets for future applications in spintronics. Using state-of-the-art electronic structure calculations, we investigate the effect of doping and disorder on their electronic and magnetic properties. Small degrees of doping by substituting Fe or Cr for Mn scarcely affect the half-metallicity. A similar effect is also achieved by mixing the sublattices occupied by the Mn and sp atoms. Thus the half-metallicity is a robust property of these alloys.

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Available from: Kemal Özdoğan, Dec 01, 2013
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    • ", such as Co 2 Mn 1 À x Cr x Z (Z¼Si, Ge, and Sn), Co 2 Mn 1 À x Fe x Z (Z¼Si, Ge, and Sn), and Co 2 [Cr 1 À x Mn x ][Al 1 À y Si y ] [19] [20] [21] "
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    ABSTRACT: We expand our study of the full-Heusler compounds [I. Galanakis , Appl. Phys. Lett. 89, 042502 (2006)] to cover also the case of doping and disorder in the case of Co2MnAl and Co2MnGa 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 Co2MnAl retains half-metallicity contrary to the Co2MnGa 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 Co(2)MnZ (Z=Si,Ge,Sn) where it was almost constant. Half-metallicity is no longer preserved for both Co2MnAl and Co2MnGa alloys when disorder occurs and there is an excess of either Mn or sp atoms.
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