Magnetization reversal in magnetic half-balls influenced by shape perturbations

Abstract

The magnetization reversal dynamics of three-dimensional ͑3D͒ ferromagnetic permalloy half-balls has been examined using micromagnetic simulations and finite element methods. The comparison between disturbed and nondisturbed sample shapes enabled observations of the nature of switching, types of oscillations, and times of reversal, triggered by an externally applied magnetic field.

Anatomy of Demagnetizing and Exchange Fields in Magnetic Nano-Dots Influenced by 3D Shape Modifications

“…3c, 3d, and 3e) produce smooth reversible magnetization curves. Such a reversible magnetization curve of quasi-spherical Fe particles of 200 nm diameter has also been found by Diao et al 36 However, investigation of the magnetization dynamics 35 and the colour-coded insets in Fig. 3c shows that here a flux-closed state is generated, corresponding to two possible states with flux rotational direction clockwise or counter-clockwise, enabling the utilization of these nano-magnets in storage devices as well.…”

Micromagnetic Simulation of Vortex Development in Magnetic Bi-Material Bow-Tie Structures

“…One advantage of such vortex states is the reduction of stray fields and thus of interactions with neighboring nanoparticles [11,12], although such interactions are not fully suppressed [13]. Flux-closed vortex states can be created in round, elliptical or square nano-rings without a core region, again reducing stray fields [14][15][16][17][18], while nano-dots of different shapes with a core region may enable formation of more magnetic states [19][20][21][22].…”

“…An overview of the possible production of such structures is given in Materials and Methods. stray fields [14][15][16][17][18], while nano-dots of different shapes with a core region may enable formation of more magnetic states [19][20][21][22].…”

Néel type magnetostatic coupling in perpendicular anisotropy bilayers -Micromagnetic simulations

“…An obvious alternative for an analytical description of the magnetostatic coupling, which we pursue in this work, is use of micromagnetic simulations (). Such simulations can provide an approximate () description of both a quasi‐static magnetization configuration as well as that of dynamics of magnetization reversal . In this work, we use the magnetostatic simulations to calculate approximately the coupling energy between the two wavy ferromagnetic layers.…”