{
  "id": "1203.0104",
  "version": "v1",
  "published": "2012-03-01T07:20:42.000Z",
  "updated": "2012-03-01T07:20:42.000Z",
  "title": "A first-principles study of tunneling magnetoresistance in Fe/MgAl2O4/Fe(001) magnetic tunnel junctions",
  "authors": [
    "Yoshio Miura",
    "Shingo Muramoto",
    "Kazutaka Abe",
    "Masafumi Shirai"
  ],
  "comment": "5 pages, 6 figures, 1 table",
  "categories": [
    "cond-mat.mes-hall"
  ],
  "abstract": "We investigated the spin-dependent transport properties of Fe/MgAl2O4/Fe(001) magnetic tunneling junctions (MTJs) on the basis of first-principles calculations of the electronic structures and the ballistic conductance. The calculated tunneling magnetoresistance (TMR) ratio of a Fe/MgAl2O4/Fe(001) MTJ was about 160%, which was much smaller than that of a Fe/MgO/Fe(001) MTJ (1600%) for the same barrier thickness. However, there was an evanescent state with delta 1 symmetry in the energy gap around the Fermi level of normal spinel MgAl2O4, indicating the possibility of a large TMR in Fe/MgAl2O4/Fe(001) MTJs. The small TMR ratio of the Fe/MgAl2O4/Fe(001) MTJ was due to new conductive channels in the minority spin states resulting from a band-folding effect in the two-dimensional (2-D) Brillouin zone of the in-plane wave vector (k//) of the Fe electrode. Since the in-plane cell size of MgAl2O4 is twice that of the primitive in-plane cell size of bcc Fe, the bands in the boundary edges are folded, and minority-spin states coupled with the delta 1 evanescent state in the MgAl2O4 barrier appear at k//=0, which reduces the TMR ratio of the MTJs significantly.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2012-03-01T07:20:42.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "72.25.Mk",
      "73.40.Rw",
      "85.75.Dd"
    ],
    "keywords": [
      "magnetic tunnel junctions",
      "tunneling magnetoresistance",
      "fe/mgal2o4/fe",
      "first-principles study",
      "in-plane cell size"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1103/PhysRevB.86.024426",
      "journal": "Physical Review B",
      "year": 2012,
      "month": "Jul",
      "volume": 86,
      "number": 2,
      "pages": "024426"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 5,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2012PhRvB..86b4426M"
    }
  }
}