Fabrication of perpendicularly magnetized magnetic tunnel junctions with L10-CoPt/Co2MnSi hybrid electrode

Magnetic tunnel junctions (MTJs) of perpendicularly magnetized L1(0)-CoPt/Co2MnSi/MgO/FePt structure were fabricated. In-plane x-ray diffraction measurements and element specific evaluation of magnetic properties using soft x-ray magnetic circular dichroism were carried out to examine quite thin Co2MnSi (CMS) inserted layer between CoPt and MgO interface. Ordered B2-CMS was successfully fabricated onto L1(0)-CoPt as thin as 1 nm thick, and CMS layer shows perpendicular magnetic anisotropy below 3 nm thick via exchange coupling with CoPt layer. In the MTJ-stacking, epitaxial growth was confirmed except for partial misalignment in the upper FePt layer, and coercive field difference clearly appeared between the bottom and the top ferromagnetic electrodes. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3358239]