Magnetization switching dynamics in barium-ferrite nano-dot: dependence on magnetic damping constant

Abstract

The Landau-Lifshift-Gilbert equation had been employed to study the effect of Gilbert damping on the dynamics of nano-Barium-Ferrite magnetization. This damping factor is necessary to investigate because of its impact on the dynamics of magnetization switching. In this study, Barium-Ferrite was chosen for study because it has large magnetic anisotropy, excellent chemical stability, and corrosion-free, potentially to be used as a magnetic storage medium with high-density. The nano-Barium-Ferrite magnetic parameters used were the anisotropy constants 3.0 × 106 erg/cm3, 4800 G saturation magnetization, 6.3 × 10−7 erg/cm exchange field, and Gilbert damping factor which varied from 0.4 to 0.9. By using the Micro-magnetic Simulator software, Nano-Barium-Ferrite was simulated as a dot with surface-sized 50 × 50 nm2 and 20 nm of the thickness. The simulation was conducted using Reduced Barrier Writing (RBW) scheme in which the sample was conditioned at room temperature of 298 K while induced by an external magnetic field. The magnetic field intensity linearly enlarged from 0 to 2 Tesla in 2.5 ns. As a result, the magnetization rate rises exponentially to the increase of Gilbert damping values at room temperature. Furthermore, the magnitude of Gilbert damping gives an impact on the propagation direction of the domain wall.