Patterning magnetic antidot-type arrays by Ga+ implantation

Motivated by reports of the effect of ion irradiation on the magnetic properties of thin films, this paper outlines a new and possibly advantageous method of patterning magnetic antidot-type arrays by changing the magnetic properties of thin-film NiFe through Ga⁺ implantation rather than by removal of material. Studies of conventional antidot arrays have reported regular remanent states of interest as possible stored bits trapped during hard axis magnetization reversal. In this paper, we report a study of Ga⁺ implanted antidot-type arrays, which also support remanent states during hard and easy axis magnetization reversal. The energetics of the implanted antidot-type array system are considered, and the reason for the different magnetization reversal process in comparison with conventional antidot arrays is speculated to be due to the energy associated with the increased coercivity and domain wall pinning at implantation-induced damage sites.