Dependence of interface anisotropy on rare earth in R/Mo (R=Dy,Er) multilayers

We report on the magnetic properties of Er/Mo multilayers and compare to our earlier work on Dy80Ni20/Mo multilayers. The magnetic order in these multilayers is not collinear and most likely is speromagnetic, much like a spin glass. Magnetic fields as high as 55 kOe do not saturate the magnetization. Both the interface anisotropy Ks and the bulk anisotropy are determined. We find a qualitative correlation between Ks and the single ion anisotropy (calculated from the bulk anisotropy) with Dy multilayers where the single ion anisotropy is larger having a larger value of Ks than Er multilayers.