Development of high-sensitive magnetoresistance devices using half-metallic Heusler alloy Co_2MnSi

Abstract

In the recent spintronics field, magnetoresistive devices using half-metals have been extensively studied. In our study, the magnetic tunnel junctions (MTJs) and CPP-GMR devices using half-metallic Heusler alloy Co_2MnSi were fabricated. Giant TMR ratio over 500% was observed in the MTJ using Al-O barrier, which clearly indicates high spin-polarization of Co_2MnSi. In addition, the fully-epitaxial CPP-GMR devices using Cr interlayer showed large MR effect exceeding that in 3d transition metals based devices.