Numerical Simulation Study of Magnetization Precession Dynamics in Submicrometer Elliptical Ni Fe Thin-Film Elements

Nonequilibrium magnetization configuration and magnetic switching behavior are studied using micromagnetic modeling. In particular, it is found that coherent rotation and magnetization ringing in submicrometer Ni₈₀Fe₂₀ elements can be controlled by adjusting the axis-ratio of the ellipse, the thickness, and the angle of the magnetic field pulse with respect to the axis of elliptical elements. For the element with 400-nm-long axis, 200-nm-short axis, and 4.7-nm thickness, the nonuniform distribution of magnetization results from a strong in-plane, nonuniform demagnetization field during magnetization precession. The simulation results indicate that uniformity in the distribution of the magnetization during reversal is improved by reducing the length of the short axis from 200 nm to 112 nm, and reducing the thickness of the thin film from 4.7 to 3.2 nm. The modification in the geometric configuration of the element is found to effectively suppress the magnetization ringing