Visible to the public Micromagnetic Simulation in Hexagonal Arrays of Nanosized Hollow Nickel Spheres

TitleMicromagnetic Simulation in Hexagonal Arrays of Nanosized Hollow Nickel Spheres
Publication TypeJournal Article
Year of Publication2016
AuthorsGuerra, Y., Gomes, J. L., Peña-Garcia, R., Delgado, A., Farias, B. V. M., Fuentes, G. P., Gonçalves, L. A. P., Padrón-Hernández, E.
JournalIEEE Transactions on Magnetics
Date PublishedNov. 2016
Keywordsangular dependence, coercive field, coercive force, composability, compositionality, cyber physical systems, demagnetisation, dynamic regime, equilibrium configurations, hexagonal arrays, Hollow spheres, hysteresis curves, magnetic array, Magnetic domains, magnetic field, magnetic hysteresis, magnetic moments, magnetic particles, magnetic properties, Magnetic Remanence, magnetic response, Magnetic separation, magnetisation reversal, Magnetization, magnetization curves, magnetization reversal, Magnetostatics, micromagnetic simulation, micromagnetics, nanomagnetics, nanoparticles, nanosized hollow nickel spheres, Ni, Nickel, nonhomogeneous configuration, Object Oriented Micromagnetic Frame-work (OOMMF), object oriented micromagnetic framework, onion modes, Perpendicular magnetic anisotropy, pubcrawl, reduced remanence, remanence, Resiliency, self-demagnetizing effects, shape effects, static regime, vortex modes

Arrays of nanosized hollow spheres of Ni were studied using micromagnetic simulation by the Object Oriented Micromagnetic Framework. Before all the results, we will present an analysis of the properties for an individual hollow sphere in order to separate the real effects due to the array. The results in this paper are divided into three parts in order to analyze the magnetic behaviors in the static and dynamic regimes. The first part presents calculations for the magnetic field applied parallel to the plane of the array; specifically, we present the magnetization for equilibrium configurations. The obtained magnetization curves show that decreasing the thickness of the shell decreases the coercive field and it is difficult to obtain magnetic saturation. The values of the coercive field obtained in our work are of the same order as reported in experimental studies in the literature. The magnetic response in our study is dominated by the shape effects and we obtained high values for the reduced remanence, Mr/MS = 0.8. In the second part of this paper, we have changed the orientation of the magnetic field and calculated hysteresis curves to study the angular dependence of the coercive field and remanence. In thin shells, we have observed how the moments are oriented tangentially to the spherical surface. For the inversion of the magnetic moments we have observed the formation of vortex and onion modes. In the third part of this paper, we present an analysis for the process of magnetization reversal in the dynamic regime. The analysis showed that inversion occurs in the nonhomogeneous configuration. We could see that self-demagnetizing effects are predominant in the magnetic properties of the array. We could also observe that there are two contributions: one due to the shell as an independent object and the other due to the effects of the array.

Citation Keyguerra_micromagnetic_2016