Coherent tunnelling conductance in magnetic tunnel junctions of half-metallic full Heusler alloys with MgO barriers

Yoshio Miura, Hirohisa Uchida, Yoshihiro Oba, Kazutaka Abe, Masafumi Shirai

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60 Citations (Scopus)

Abstract

We have carried out electronic structure and transport calculations for magnetic tunnel junctions (MTJ) composed of MgO and a half-metallic full Heusler alloy Co2MnSi on the basis of the density functional theory and the Landauer formula. We find that the density of states of Co atoms at the Co 2MnSi/MgO(001) interface shifts toward the higher energy side due to the reduced symmetry, leading to a reduction of the spin polarization at the interface. Furthermore, we show that the majority-spin transmittance as a function of the in-plane wavevector has a broad peak centred at due to the tunnelling from the Δ1 channel of Co2MnSi, while the transmittance from the Δ5 channel is three orders of magnitude smaller than that of the Δ1 channel. These results indicate that coherent tunnelling through the Δ1 band is dominant also in an MTJ with Co2MnSi and an MgO barrier, like in Fe/MgO/Fe(001) MTJ and related systems.

Original languageEnglish
Article number365228
JournalJournal of Physics Condensed Matter
Volume19
Issue number36
DOIs
Publication statusPublished - 2007 Sep 12

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics

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