Observation Of Domain Wall Creep Motions In Co/Ni Multilayers Interfacing With Irmn Layer

We report the experimental observation of the domain wall creep motion in the ferromagnetic CoNi multilayers interfacing with antiferromagnetic IrMn layer, using a magento-optical Kerr microscope system capable of direct observation of domain change. From the magnetic domain images observed in real time, it can be seen that as the IrMn thickness increases from 0 angstrom to 25 angstrom, the strength of the magnetic field required to move the magnetic domain wall gradually increases, due to an increase in coercivity due to the exchange bias effect at the interface. In addition, it was found that the magnetic domain wall velocity characteristics according to the magnetic field in all samples were well explained by the thermal activated model assuming the domain wall creep motion.