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Title: Testing epitaxial Co{sub 1.5}Fe{sub 1.5}Ge(001) electrodes in MgO-based magnetic tunnel junctions

The ability of the full Heusler alloy Co{sub 1.5}Fe{sub 1.5}Ge(001) (CFG) to be a Half-Metallic Magnetic (HMM) material is investigated. Epitaxial CFG(001) layers were grown by molecular beam epitaxy. The results obtained using electron diffraction, X-ray diffraction, and X-ray magnetic circular dichroism are consistent with the full Heusler structure. The pseudo-gap in the minority spin density of state typical in HMM is examined using spin-resolved photoemission. Interestingly, the spin polarization found to be negative at E{sub F} in equimolar CoFe(001) is observed to shift to positive values when inserting Ge in CoFe. However, no pseudo-gap is found at the Fermi level, even if moderate magnetization and low Gilbert damping are observed as expected in HMM materials. Magneto-transport properties in MgO-based magnetic tunnel junctions using CFG electrodes are investigated via spin and symmetry resolved photoemission.
Authors:
 [1] ;  [2] ; ; ; ;  [1] ; ; ;  [3] ;  [4] ;  [5] ; ;  [6]
  1. Institut Jean Lamour, UMR CNRS 7198, Université de Lorraine, 54506 Vandoeuvre lès Nancy (France)
  2. (France)
  3. Synchrotron SOLEIL-CNRS, L'Orme des Merisiers, Saint-Aubin BP48, 91192 Gif-sur-Yvette (France)
  4. Institut d'Electronique Fondamentale, CNRS, UMR 8622, 91405 Orsay (France)
  5. Department of Physics and Astronomy/Center for Materials for Information Technology, University of Alabama, Tuscaloosa, Alabama 35487 (United States)
  6. San Jose Research Center, HGST, a Western Digital company, San Jose, California 95135 (United States)
Publication Date:
OSTI Identifier:
22303861
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 25; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; COBALT COMPOUNDS; ELECTRIC CONDUCTIVITY; ELECTRODES; ELECTRON DIFFRACTION; GERMANIUM COMPOUNDS; HEUSLER ALLOYS; IRON COMPOUNDS; LAYERS; MAGNESIUM OXIDES; MAGNETIC CIRCULAR DICHROISM; MAGNETIC MATERIALS; MAGNETIZATION; MOLECULAR BEAM EPITAXY; PHOTOEMISSION; SPIN ORIENTATION; SYMMETRY; TUNNEL EFFECT; X RADIATION; X-RAY DIFFRACTION