Antidot effects on micromagnetic behavior of Py ferromagnetic samples

• The choice of antidot parameters in a finite sized Py film affects the magnetic reversal process.
• The antidot pattern causes the formation of SDs and LE-SDWs at nano-meter scales.
• A significant increase in the coercivity is found for the sample with the largest number of antidots.

The coercivity and magnetic hysteresis behavior of permalloy (Py) samples have been studied in the presence of square arrays of the circular antidots. The open source OOMMF micromagnetic software is used to numerically solve the Landau–Lifshitz–Gilbert (LLG) equation. In calculations, Py samples are designed in such a way that they include a different number of antidot in an array which possess the same total surface area. In this way, the total Py region stayed unchanged despite the growing number of antidots in a fixed sample size. We found significant increase in the coercive field for the sample with the smallest antidot spacing. The results are discussed within the framework of superdomain (SD) and superdomain wall (SDW) formation.