Tunnel Magnetoresistance Effect in CoFeB/MgO/Heusler Alloys(Co2FeSi, Co2MnSi) Tunnel Junctions

Abstract

In this study, we investigated the TMR effects in CoFeB/MgO/Heusler alloys (Co2FeSi and Co2MnSi) magnetic tunnel junctions. Both Co2FeSi and Co2MnSi heusler alloys have half-metallic band structure and high Curie temperature of 1200K and 985K, respectively. Moreover, the lattice mismatch between the Heusler alloys and MgO barrier is relatively small, which indicates that the highly textured Heusler alloys can be grown on the MgO barrier. In addition, it could be noted that spin-fluctuation at finite temperature can reduce spin-polarization of Heusler alloys even though the MgO/Heusler alloys is ideal HMFs at low temperature.