Title :
Magnetic properties of epitaxial Co2Cr1-xFexAl full Heusler alloy thin films with the L21 structure
Author :
Hirohata, Astufumi ; Kurebayashi, Hidekazu ; Okamura, Susumu ; Tezuka, Nobuki ; Inomata, Koichiro
Author_Institution :
CREST, Japan Sci. & Technol. Agency, Kawaguchi, Japan
Abstract :
Co2Cr1-xFexAl full Heusler alloy thin films (x≥0.4) have been epitaxially grown on GaAs(001) substrates under the optimized condition. Structural analysis reveals the detailed growth mechanism of the films and confirms that the films form the perfectly ordered L21 structure. A magnetization measurement also shows the films possess very strong uniaxial crystalline anisotropy due to the epitaxial growth. By using these films as bottom electrodes of magnetic tunnel junctions, the maximum tunnel magnetoresistance ratio of 8.8% is observed after post-annealing with Al-O insulating barriers for x=1.
Keywords :
chromium alloys; cobalt alloys; crystal microstructure; iron alloys; magnetic anisotropy; magnetic epitaxial layers; tunnelling magnetoresistance; Co2CrFeAl; GaAs; L21 structure; annealing; epitaxial growth; full Heusler alloy thin films; growth mechanism; half-metallic ferromagnets; insulating barriers; magnetic properties; magnetic tunnel junctions; magnetization measurement; structural analysis; tunnel magnetoresistance; uniaxial crystalline anisotropy; Aluminum alloys; Chromium alloys; Cobalt alloys; Iron alloys; Magnetic analysis; Magnetic films; Magnetic properties; Magnetization; Substrates; Transistors; Epitaxial growth; full Heusler alloys; half-metallic ferromagnets; tunnel magnetoresistance;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2005.854831
