Co2MnSi Heusler alloy as an enhancing layer of perpendicular magnetic anisotropy for MgO-based magnetic tunnel junctions with L10 ordered FePd

Ultra-thin Co2MnSi Heusler alloy improves perpendicular magnetic anisotropy of FePd in an MgO-based magnetic tunnel junction after annealing it just once at a temperature of as low as 400 °C. Co2MnSi as thin as 1.0 nm inserted between MgO and FePd facilitated phase-transformation of 3-nm-thick FePd to ordered L10 and led a change in magnetic anisotropy to perpendicular-to-the-plane. To make it even better, FePd also helped the phase-transformation of Co2MnSi to ordered B2 known to have high spin polarization, which makes the L10 FePd/B2 Co2MnSi bilayer promising for perpendicular-magnetic tunnel junction and improving both thermal stability and tunnel magnetoresistance.