Relaxation time and thermal stability in magneto-optical recording media

The time dependence of the magnetization process in amorphous TbFeCo thin films and (TbFeCo/Pt) multilayers is studied. By assuming a Gaussian distribution of relaxation times for magnetic aftereffect, the non-Arrhenius behavior of the magnetization decay is found in almost all samples. From a fitting of experimental data one can determine the mean value of relaxation time /spl tau//sub 0/ and also its width /spl Delta//spl tau//sub 0/. The multilayers of TbFeCo/Pt show a high stability compared to single layers of TbFeCo with also a small activation volume.