Transport and switching behaviors in magnetic tunnel junctions consisting of CoFeB/FeNiSiB hybrid free layers

We report the efficacy of CoFeB/FeNiSiB hybrid ferromagnetic layers as free layers in magnetic tunnel junctions. A junction with a CoFeB (2.25 nm)/FeNiSiB (0.75 nm) free layer exhibited a tunneling magnetoresistance ratio and a resistance-area product value of 130% and 25 Ωμm2, respectively. The critical current density for spin transfer torque (STT) switching was 2.3 MA/cm2. This study suggests that the addition of an amorphous FeNiSiB in the free layer enhances the magnetotransport properties.