Abstract
The magnetic anisotropy of (111)Pt/Co and Pt/Co/Ag superlattices (SLs) grown on 7×7 -(111)Si by molecular beam epitaxy was studied. The interface anisotropy K s of Pt/Co SLs is found to be 1.29 mJ/m2, which is much larger than the value reported previously. The effective anisotropy energy K ef f of Pt/Co/Ag SLs is similar to the average of K ef f values of Pt/Co and Ag/Co SLs with the same Co layer thickness. This suggests that the origins of perpendicular anisotropy in the Pt/Co system are different from those in the Au/Co system investigated earlier, in which the difference between the K ef f values of Au/Co and Au/Co/Ag SLs is small.