Title :
Perpendicular Magnetization of Ta/Ru/Ta/Co/Fe/MgO Multilayer
Author :
Joon Pyo Kil ; Yeonhoi Choi ; Gi Yoon Bae ; Hyungsik Oh ; Won Joon Choi ; Wanjun Park
Author_Institution :
Dept. of Electron. Eng., Hanyang Univ., Seoul, South Korea
Abstract :
Ta/Ru/Ta/Co/Fe/MgO film is studied to investigate the separate roles of Co and Fe in perpendicular magnetic anisotropy. Perpendicular magnetization is successfully obtained in this structure after a field annealing process (275 °C, 3 T, 30 min). Surface magnetic anisotropy at the Fe/MgO interface induces perpendicular magnetization for the Co/Fe bilayer with the critical contribution of the inserted Co. Magnetization properties resulting from the use of various Co and Fe layer thicknesses in the range of 0.36-0.6 nm (Co) and 0.52-0.91 nm (Fe) are analyzed, indicating the formation of a magnetic dead layer between the Co layer and the Ta seed layer. The maximum effective anisotropy energy (Keff) is estimated as 1.63 × 105 J/m3 for Co (0.36 nm)/Fe (0.65 nm).
Keywords :
annealing; cobalt; iron; magnesium compounds; magnetic multilayers; magnetic thin films; magnetisation; perpendicular magnetic anisotropy; ruthenium; surface magnetism; tantalum; Co layer thickness; Co-Fe bilayer; Fe layer thickness; Fe-MgO interface; Ta seed layer; Ta-Ru-Ta-Co-Fe-MgO; Ta-Ru-Ta-Co-Fe-MgO film; Ta-Ru-Ta-Co-Fe-MgO multilayer; field annealing process; magnetic dead layer formation; maximum effective anisotropy energy; perpendicular magnetic anisotropy; perpendicular magnetization; size 0.36 nm to 0.91 nm; surface magnetic anisotropy; temperature 275 degC; time 30 min; Anisotropic magnetoresistance; Films; Iron; Magnetic tunneling; Magnetization; Perpendicular magnetic anisotropy; Fe/MgO; interfacial anisotropy; magnetic tunnel junction; magnetic tunnel junction (MTJ); perpendicular magnetic anisotropy; perpendicular magnetic anisotropy (PMA);
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2015.2438324
