Resonantly excited precession motion of three-dimensional vortex core in magnetic nanospheres

• DOI: 10.1038/srep11370
• Publication Date: 2015-06-16T13:04:58Z
• Authors: Sang-Koog Kim; Myoung-Woo Yoo; Jehyun Lee; Ha-Youn Lee; Jae-Hyeok Lee; Yuri Gaididei; Volodymyr P. Krav...; Denis D. Sheka
• Keywords: Precession; Gyromagnetic ratio; Micromagnetics; Larmor precession; Vortex state; Magnetization dynamics

Abstract We found resonantly excited precession motions of a three-dimensional vortex core in soft magnetic nanospheres and controllable frequency with the sphere diameter 2 R , as studied by micromagnetic numerical analytical calculations. The angular for an applied static field H DC is given ω MV = γ eff where γ〈 m Γ 〉 effective gyromagnetic ratio collective dynamics, average magnetization component 〈 ground-state direction. Fitting to simulation data yields simple explicit form ≈ (73.6 ± 3.4)( l ex /2 ) 2.20±0.14 exchange length material. This dynamic behavior might serve foundation potential bio-applications size-specific resonant excitation vortex-state nanoparticles, example, particle resonance imaging.