Thickness Dependence of Creep-Scaling behavior in Pt/Co Single Interface Films

We report here the ferromagnetic-layer thickness dependence of the creep-scaling behavior in Pt/Co single interface films. By means of an in-vacuum magneto-optical Kerr effect microscope, the magnetization dynamics were observed in the films with different Co layer thickness. From the clear domain-wall creep-scaling behaviors, the creep-scaling constant was determined and analyzed with respect to the Co layer thickness. The thickness dependence of the creep-scaling constant manifests the formation of a ferromagnetic dead layer, the thickness of which is roughly about one monoatomic layer. By excluding the dead-layer thickness, it becomes clear that the effective magnetic layer thickness is proportional to the creep-scaling constant, confirming the validity of the creep-scaling theory.