Large magnetoresistance in FeÕMgOÕFeCo„001... epitaxial tunnel junctions on GaAs„001..
نویسندگان
چکیده
We present tunneling experiments on Fe~001!/MgO~20 Å!/FeCo~001! single-crystal epitaxial junctions of high quality grown by sputtering and laser ablation. Tunnel magnetoresistance measurements give 60% at 30 K, to be compared with 13% obtained recently on ~001!-oriented Fe/amorphous-Al2O3 /FeCo tunnel junctions. This difference demonstrates that the spin polarization of tunneling electrons is not directly related to the density of states of the free metal surface— Fe~001! in this case—but depends on the actual electronic structure of the entire electrode/barrier system. © 2001 American Institute of Physics. @DOI: 10.1063/1.1404125#
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