Visible to the public Peak in Angular Dependence of Coercivity in a Hexagonal Array of Permalloy Spherical Nanocaps

TitlePeak in Angular Dependence of Coercivity in a Hexagonal Array of Permalloy Spherical Nanocaps
Publication TypeJournal Article
Year of Publication2019
AuthorsDavila, Y. G., Júnior, F. A. Revoredo, Peña-Garcia, R., Padrón-Hernández, E.
JournalIEEE Magnetics Letters
Keywordscoercive force, coercivity, composability, compositionality, cyber physical systems, demagnetisation, demagnetizing field, dipole energy, external magnetic field direction, ferromagnetic nanocaps, Geometry, hemispherical Permalloy nanocaps, hexagonal array, hysteresis loops, Internet of Things, Magnetic anisotropy, Magnetic domains, magnetic hysteresis, magnetic moments, Magnetic Remanence, magnetisation reversal, Magnetization, magnetization reversal, magnetization reversal mechanism, micromagnetic simulation, micromagnetic simulations, micromagnetics, nanomagnetics, nanostructured materials, Permalloy, pubcrawl, remanence, Resiliency, shape anisotropy, size 10.0 nm, size 5.0 nm

Micromagnetic simulations of coercivity as a function of external magnetic field direction were performed for a hexagonal array of hemispherical Permalloy nanocaps. The analysis was based on hysteresis loops for arrangements of nanocaps of variable thickness (5 nm and 10 nm). The angular dependence of coercivity had a maximum at about 80deg with respect to the arrangement plane. An increase in coercivity with nanocap thickness is related to the magnetization reversal mechanism, where the dipole energy of individual caps generates an effective intermediate axis, locking the magnetic moments. The coercivity has maximum values of 109 Oe for 5 nm and 156 Oe for 10 nm thickness. The remanence decreases monotonically with angle. This is associated with the influence of shape anisotropy, where the demagnetizing field in the plane of the array is much smaller than the demagnetizing field perpendicular to the plane.

Citation Keydavila_peak_2019