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

Journal Article · Mon Jun 23 00:00:00 EDT 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4885354· OSTI ID:22303861

Neggache, A. ^[1]; Hauet, T.; Petit-Watelot, S.; Boulet, P.; Bertran, F.; Le Fèvre, P.; Ohresser, P. ^[2]; Devolder, T. ^[3]; Mewes, C. ^[4]; Maat, S.; Childress, J. R. ^[5]

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1. Institut Jean Lamour, UMR CNRS 7198, Université de Lorraine, 54506 Vandoeuvre lès Nancy (France)
2. Synchrotron SOLEIL-CNRS, L'Orme des Merisiers, Saint-Aubin BP48, 91192 Gif-sur-Yvette (France)
3. Institut d'Electronique Fondamentale, CNRS, UMR 8622, 91405 Orsay (France)
4. Department of Physics and Astronomy/Center for Materials for Information Technology, University of Alabama, Tuscaloosa, Alabama 35487 (United States)
5. San Jose Research Center, HGST, a Western Digital company, San Jose, California 95135 (United States)

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.

• OSTI ID: 22303861
• Journal Information: Applied Physics Letters, Vol. 104, Issue 25; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

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