MAGNETIC-PROPERTIES OF COXNI1-X/PT MULTILAYERS

We have prepared CoxNi1-x/Pt multilayers by evaporation under ultrahigh vacuum conditions and studied their magnetic and magneto-optical properties. The addition of Co to Ni leads to an increase in both the surface anisotropy and T(C). It is found that the surface anisotropy K(s) of CoxNi1-x/Pt multilayers can be expressed as the sum of K(s) of Ni/Pt and of Co/Pt times their respective concentration. In Co0.3Ni0.7/Pt multilayers, for t(Co,Ni)=0.45 nm, one observes a perpendicular M-H loop with a good rectangularity and a coercivity of 1 kOe and T(C) of 180-degrees-C. These characteristics are very interesting for application in magneto-optic storage.