The annealing effect and the origin of perpendicular anisotropy in amorphous GdTbFe film

The effect of annealing on the magnetic anisotropy and the thermal stability has been investigated for an amorphous Gd₂₇Tb₁₀Fe₆₃ film prepared by magnetron sputtering. On the basis of a pseudodipolar interaction, a numerical computation is performed primarily on fitting a variance of the anisotropy constant with that of the thermal annealing at various temperatures and shows that a contribution from Tb-Fe pairs are dominant in determining the perpendicular anisotropy. H_c = K_u/M_s is used to describe the variance of coercivity after that heat treatment. The behaviour of annealing the films in air shows that the films with a protective Al film possess a good thermal stability for magneto-optical recording.