Tailoring of magnetic properties of patterned cobalt antidots by simple manipulation of lattice symmetry

Abstract

Cobalt (Co) antidot arrays with different lattice geometries, square and rhomboid structures were fabricated and their magnetic reversal properties were studied by scanning-electron microscopy (SEM), magneto-optic Kerr effect, and magnetic force microscopy (MFM). Different lattice symmetries induced the corresponding anisotropies with changing easy and hard axes. The nearest-neighbor rule is not applicable in case of the rhomboid antidot lattice, while the inclusion theory is. These results are different from those of the previous investigations. The differences are due to different sizes and spacing’s between the antidots. The MFM images in the remanent state showed well-defined domain structures, periodic in nature according to the lattice geometry.

A micromagnetic study of the reversal mechanism in permalloy antidot arrays

“…9,22,27,37 This can be due to differences in the magnetocrystalline anisotropy of the sample material, in the hole shape and size, and in the spatial period. As an example, the hole shape has a strong influence on the coercive field and remanent magnetization values.…”

“…2(a) of Ref. 22, measured by vibrating sample magnetometer (VSM) and magneto-optic Kerr effect (MOKE), respectively. Specifically, they are characterized by a gradual switching in the magnetization and by three kinks, occurring at the beginning of the reversal process, at the coercive field and before reaching saturation in the negative direction.…”

“…[4][5][6][7][8] Magnetotransport and hysteresis properties have been investigated in detail, considering different materials and analyzing the role of lattice configuration, hole shape, and geometrical parameters, such as the hole size and the interhole distance. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] Magnetic domain structures arising in antidot arrays have been experimentally observed by means of magnetic force microscopy (MFM), Lorentz microscopy, X-ray photoemission electron microscopy, and magnetooptic Kerr effect measurements. [22][23][24][25][26][27][28][29] The patterning introduces a spatially dependent shape anisotropy that allows the nucleation and propagation of domain walls, influencing in this way the reversal mechanism, the remanent magnetization, and the coercive field.…”

“…[9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] Magnetic domain structures arising in antidot arrays have been experimentally observed by means of magnetic force microscopy (MFM), Lorentz microscopy, X-ray photoemission electron microscopy, and magnetooptic Kerr effect measurements. [22][23][24][25][26][27][28][29] The patterning introduces a spatially dependent shape anisotropy that allows the nucleation and propagation of domain walls, influencing in this way the reversal mechanism, the remanent magnetization, and the coercive field. [9][10][11][12][13][14][15][16] A fourfold anisotropy has been found in square-lattice geometries, while hexagonal and honeycomb configurations exhibit a sixfold symmetry.…”

Tailoring the magnetic properties of cobalt antidot arrays by varying the pore size and degree of disorder

“…In an antidot array, magnetic features such as coercive field, anisotropy axes and reversal mechanisms, among others, can be tailored by tuning the geometric parameters of the array [18,19,20]. Such parameters are: the shape and diameter of the hole, the distance between holes and their spatial distribution.…”