Micromagnetic Simulation on the Interelement Coupling of High-Density Patterned Film

In this paper, the magnetic properties of an individual square permalloy (Ni₈₀Fe₂₀) nanoelement at the center of an array with both in-plane shape anisotropy and interelement interaction were investigated by the 3-D object oriented micromagnetic framework. Variation of the interelement coupling was studied by changing the element lateral size (a) and interelement spacing (s). Magnetic hysteresis loop and dependence of saturation field on s/a (R) of the individual element at the center of array indicate that dipolar interaction dominates the magnetic properties of array with small R (R ≤ 1), whereas at R > 1, the interelement interaction can be ignored, and therefore, the shape anisotropy plays an important role in determining both the strength and the direction of magnetic moments. Moreover, for small R, the global easy axis is along the direction of element edge, and with increasing R, the easy axis appears to gradually turn to the diagonal direction. It is noteworthy that the corresponding conversion points of the easy axis on R decrease from 0.6 to 0.3 as increasing a from 10 to 20 nm, indicating the effect of interelement coupling is weaker in array with a larger element lateral size. The collective magnetic behavior of array is also investigated for comparison.