Kerr rotations and anisotropy in (Pt/Co/Pt)/X multilayers

The link between interface sharpness and perpendicular magnetic anisotropy (K_⊥) in Pt/Co multilayers has been exploited to yield enhanced magnetic anisotropy in related multilayer structures. These new multilayers consist of a (Pt/Co/Pt)/Pd stacking sequence where the Pt thickness is of just one atomic monolayer. The extra interfaces per period are introduced in areas where the spin polarization is still expected to be large thus resulting in extra magnetic anisotropy. K_⊥ as high as 5×10⁷ erg/cm³ was measured in Xe sputtered films with this new period. This idea was extended to (Pt/Co/Pt)X systems with X=Ag, Cu, Ni. A ten fold increase in K_⊥ is observed in these films compared to their respective Co/X counterparts. The Kerr rotation (θK) as a function of photon wavelength is also greatly enhanced by the presence of the Pt monolayers. A strong dependence of θK on the spacer element X in these systems is observed