Micromagnetic Computation of Damping Constant Effect on Switching Mechanism of a Hexagonal Platelet Particle

The effect of Gilbert's damping constant on the switching mechanism of a magnetic hexagonal platelet particle was investigated by computer simulation. Three damping constants were used for the calculation: α=1, 0.3 and 0.1. When a uniform field is applied in the direction of the easy axis of the platelet, the average magnetization in that direction begins to oscillate. The amplitude of the oscillation, which increases with decreasing damping constant, decreases with time. Switching occurs after the oscillation ceases. The magnetic moments of the platelets switch in the vortex mode for all damping constants investigated. The switching mechanism is complicated in a small α platelet; the center of the vortex moves around in a hexagonal plane at small α (α=0.1), but the center of the vortex stays at the center at large α (α=0.3, 1).