Figure 1.

(a) Coercive field map of [Tb(t_Tb)/Co(t_Co)]₅. The coercive field values were obtained from the M(H) loops measured with H applied perpendicular to the plane of the film. The superimposed gray region in the center indicates the region in which H was not sufficient to saturate the stack. The black dashed line schematically represents the thickness values of Tb and Co for which the coercive field diverges i.e. where magnetic compensation occurs at room temperature. (b) Coercive field of [Tb/Co]₅ multilayer as a function of Co thickness t_Co: 7–13 Å with the thickness of the Tb layers fixed at t_Tb  =  10 Å. Insets: R(H) for t_Co  =  8.1 Å and t_Co  = 10.9 Å as indicated.