Regensburg 2016 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 42: Magnetic Heuslers, Half-Metals and Oxides (jointly with TT)
MA 42.9: Vortrag
Donnerstag, 10. März 2016, 11:45–12:00, H34
Chemical disorder as engineering tool for magnetic properties and spin-polarization in Mn3Ga-based Heusler systems — •Lukas Wollmann, Stanislav Chadov, Sunil Wilfred D’Souza, Gerhard H. Fecher, and Claudia Felser — Max-Planck-Insitute for Chemical Physics of Solids
The present contribution discusses the effect of random substitution of Mn in Mn3Ga as a constructive disorder phenomenon, which, for instance, allows to chemically control the spin-polarization of the charge carriers. It is based on spin-selective electron localization encountered by the first-principles calculations on the family of tetragonal Mn-based Heusler materials Mn3−xYxGa [1,2]. Our calculations indicate that spin-selective localization can be introduced by substituting Mn with almost any 3d transition metal element (Sc, Ti, V, Cr, Fe, Co, Ni, Cu) as well as with several heavier species as Os, Ir or Pt. The spin-polarization was derived from the spin-projected residual conductivity tensor computed within the Kubo-Greenwood formalism within the SPR-KKR method [3], which properly accounts for the effects of electron localization induced by the scattering due to chemical disorder. In this way one might obtain the series of highly spin-polarized alloys with noticeable magnetocrystalline anisotropy, combining the advantages of tetragonal and cubic Heusler compounds.
[1] S. Chadov et al., Phys. Rev. B 91 094203 (2015); [2] L. Wollmann et al., J. Phys. D: Appl. Phys. 48 164004 (2015); [3] H. Ebert et al., Rep. Prog. Phys. 74 096501 (2011).