Magnetic and structural properties of Co/Pt multilayers with varying Co (tCo) and Pt (tPt) thickness
grown on various seed layers have been examined. It is challenging to grow Co/Pt multilayers as a
top electrode with high perpendicular magnetic anisotropy (PMA) for magnetic tunnel junctions
which usually comprise of CoFeB/MgO/CoFeB. We show that a thicker Pt layer of 1.2 nm is
necessary to attain effective anisotropy (Keff) up to 0.14 MJ/m3. On the other hand, Co/Pt
multilayers with high PMA have been achieved for proper textured seed layers of Ru and Pt. In the
case of Ru seed layer, a higher Keff¼0.45 MJ/m3 can be achieved for tCo¼0.5 nm and tPt¼0.2 nm.
This can be attributed to the lower lattice mismatch ( 4%) within the multilayers and hence a
more coherent CoPt (111) structure. Finally, we note that the film roughness could play an
important role in influencing the PMA of the multilayers. The highest Keff 0.6 MJ/m3 is achieved
for Pt seed layer.
Copyright (2015) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in J. Appl. Phys. 117, 17A731 (2015) and may be found at http://dx.doi.org/10.1063/1.4916295.