Structural and magnetic properties of epitaxial L2{sub 1}-structured Co{sub 2}(Cr,Fe)Al films grown on GaAs(001) substrates

Journal Article · Sun May 15 00:00:00 EDT 2005 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.1888050· OSTI ID:20709654

Hirohata, A; Kurebayashi, H; Okamura, S; Kikuchi, M; Masaki, T; Nozaki, T; Tezuka, N; Inomata, K ^[1]

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1. Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan)

We have successfully grown both L2{sub 1} polycrystalline Co{sub 2}CrAl and epitaxial L2{sub 1}-structured Co{sub 2}FeAl films onto GaAs(001) substrates under an optimized condition. Both structural and magnetic analyses reveal the detailed growth mechanism of the alloys, and suggest that the Co{sub 2}CrAl film contains atomically disordered phases, which decreases the magnetic moment per f.u., while the Co{sub 2}FeAl film satisfies the generalized Slater-Pauling behavior. By using these films, magnetic tunnel junctions (MTJs) have been fabricated, showing 2% tunnel magnetoresistance (TMR) for the Co{sub 2}CrAl MTJ at 5 K and 9% for the Co{sub 2}FeAl MTJ at room temperature (RT). Even though the TMR ratio still needs to be improved for future device applications, these results explicitly include that the Co{sub 2}(Cr,Fe)Al full Heusler alloy is a promising compound to achieve half-metallicity at RT by controlling both disorder and surface structures in the atomic level by manipulating the Fe concentration.

• OSTI ID: 20709654
• Journal Information: Journal of Applied Physics, Vol. 97, Issue 10; Other Information: DOI: 10.1063/1.1888050; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM COMPOUNDS
ANISOTROPY
CHROMIUM ALLOYS
COBALT ALLOYS
CRYSTAL GROWTH
FILMS
GALLIUM ARSENIDES
HEUSLER ALLOYS
HYSTERESIS
IRON ALLOYS
MAGNETIC MOMENTS
MAGNETIC PROPERTIES
MAGNETIZATION
MAGNETORESISTANCE
MOLECULAR BEAM EPITAXY
POLYCRYSTALS
SUPERCONDUCTING JUNCTIONS
TEMPERATURE RANGE 0273-0400 K
TUNNEL EFFECT
VACUUM COATING