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

Neggache, A.; Hauet, T.; Petit-Watelot, S.; Boulet, P.; Bertran, F.; Le Fèvre, P.; Ohresser, P.; Devolder, T.; Mewes, C.; Maat, S.; Childress, J. R.

doi:10.1063/1.4885354

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

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Abstract

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:

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]

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

Publication Date:: Mon Jun 23 00:00:00 EDT 2014

OSTI Identifier:: 22303861

Resource Type:: Journal Article

Journal Name:: Applied Physics Letters

Additional Journal Information:: Journal Volume: 104; Journal Issue: 25; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0003-6951

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

Citation Formats


                    Neggache, A., Synchrotron SOLEIL-CNRS, L'Orme des Merisiers, Saint-Aubin BP48, 91192 Gif-sur-Yvette, Hauet, T., Petit-Watelot, S., Boulet, P., Andrieu, S., E-mail: stephane.andrieu@univ-lorraine.fr, Bertran, F., Le Fèvre, P., Ohresser, P., Devolder, T., Mewes, C., Maat, S., and Childress, J. R. Testing epitaxial Co{sub 1.5}Fe{sub 1.5}Ge(001) electrodes in MgO-based magnetic tunnel junctions.  United States: N. p., 2014. 
        Web.  doi:10.1063/1.4885354.

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                    Neggache, A., Synchrotron SOLEIL-CNRS, L'Orme des Merisiers, Saint-Aubin BP48, 91192 Gif-sur-Yvette, Hauet, T., Petit-Watelot, S., Boulet, P., Andrieu, S., E-mail: stephane.andrieu@univ-lorraine.fr, Bertran, F., Le Fèvre, P., Ohresser, P., Devolder, T., Mewes, C., Maat, S., & Childress, J. R. Testing epitaxial Co{sub 1.5}Fe{sub 1.5}Ge(001) electrodes in MgO-based magnetic tunnel junctions.  United States.  https://doi.org/10.1063/1.4885354

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                    Neggache, A., Synchrotron SOLEIL-CNRS, L'Orme des Merisiers, Saint-Aubin BP48, 91192 Gif-sur-Yvette, Hauet, T., Petit-Watelot, S., Boulet, P., Andrieu, S., E-mail: stephane.andrieu@univ-lorraine.fr, Bertran, F., Le Fèvre, P., Ohresser, P., Devolder, T., Mewes, C., Maat, S., and Childress, J. R. 2014.  
        "Testing epitaxial Co{sub 1.5}Fe{sub 1.5}Ge(001) electrodes in MgO-based magnetic tunnel junctions".  United States.  https://doi.org/10.1063/1.4885354.

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@article{osti_22303861,

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

  author       = {Neggache, A. and Synchrotron SOLEIL-CNRS, L'Orme des Merisiers, Saint-Aubin BP48, 91192 Gif-sur-Yvette and Hauet, T. and Petit-Watelot, S. and Boulet, P. and Andrieu, S., E-mail: stephane.andrieu@univ-lorraine.fr and Bertran, F. and Le Fèvre, P. and Ohresser, P. and Devolder, T. and Mewes, C. and Maat, S. and Childress, J. R.},

  abstractNote = {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.},

  doi          = {10.1063/1.4885354},

  url          = {https://www.osti.gov/biblio/22303861},
  journal      = {Applied Physics Letters},

  issn         = {0003-6951},

  number       = 25,

  volume       = 104,

  place        = {United States},

  year         = {Mon Jun 23 00:00:00 EDT 2014},

  month        = {Mon Jun 23 00:00:00 EDT 2014}

}

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