We studied magnetic tunnel junctions (MTJs) with a MgO(001) barrier and metastable bcc Co3Mn(001) disordered alloy electrodes. A tunnel magnetoresistance (TMR) ratio was approximately 200%–250% observed at room temperature. We successfully observed the TMR ratio greater than 600% at 10 K which was higher than the past reported value of MgO-based MTJs with ultrathin bcc Co(001) electrodes. However, our experimental value was still much lower than the past theoretical prediction in bcc Co/MgO/Co(001) MTJs. We discuss some differences in the bulk band structure affecting the TMR effect for bcc Co and bcc Co3Mn.

We fabricated MgO barrier magnetic tunnel junctions (MTJs) with a Co 3 Mn alloy bottom and FeCoB top electrodes. The (001)-oriented epitaxial films of the metastable bcc Co 3 Mn disordered alloys obtained showed saturation magnetization of approximately 1640 emu/cm 3. The transmission electron microscopy showed that the MgO barrier was epitaxially grown on the Co 3 Mn electrode.

No abstract

No abstract