Giant tunnel magnetoresistance in Co{sub}2MnSi/Al-O/Co{sub}2MnSi magnetic tunnel junctions

摘要

Half-metallic ferromagnet (HMF), which has completely spin-polarized conduction electrons due to energy gap of one spin-band at Fermi Energy, attracted much interest because of its large potential for the spin-electronics device. One of the full-Heusler alloys, Co{sub}2MnSi, is expected as an ideal HMF candidate since it has half-metallic band structure combined with high Curie temperature of 985K. In our previous work, we have synthesized highly L2{sub}1-ordered Co{sub}2MnSi epitaxial electrode and applied it the bottom electrode of magnetic tunnel junction (MTJ)[1]. Fabricated MTJ with Co{sub}2MnSi/Al-O/Co{sub}75Fe{sub}25 structure have exhibited a magnetoresistance (MR) ratio of 159% and at 2K, which was the highest value that has been reported in the MTJ using Al-O amorphous barrier. In this study, we attempt to fabricate a MTJ using Co{sub}2MnSi as both upper and lower electrodes.