Perpendicular Magnetization of Ta/Ru/Ta/Co/Fe/MgO Multilayer

摘要

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 is estimated as 1.63 105 J/m for Co (0.36 nm)/Fe (0.65 nm).