Fabrication of magnetic tunnel junctions with a metastable bcc Co3Mn disordered alloy as a bottom electrode

We fabricated MgO barrier magnetic tunnel junctions (MTJs) with a Co3Mn alloy bottom and FeCoB top electrodes. The (001)-oriented epitaxial films of the metastable bcc Co3Mn 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 Co3Mn electrode. Tunnel magnetoresistance of approximately 150% was observed at room temperature after the annealing of MTJs at 350 degrees C, indicating that bcc Co3Mn alloys have relatively high spin polarization. (C) 2019 The Japan Society of Applied Physics