MAGNETIC-PROPERTIES OF COXNI1-X PT MULTILAYERS/

We have prepared CoxNi1-x/Pt multilayers by evaporation under ultrahig h vacuum conditions and studied their magnetic and magneto-optical pro perties. The addition of Co to Ni leads to an increase in both the sur face 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 l oop with a good rectangularity and a coercivity of 1 kOe and T(C) of 1 80-degrees-C. These characteristics are very interesting for applicati on in magneto-optic storage.