COMPUTER-SIMULATION OF MAGNETIZATION REVERSAL MECHANISMS OF HEXAGONAL PLATELET PARTICLE - EFFECT OF MATERIAL PARAMETERS

The effect of material parameters on the switching mechanism and switching field, H(sw), of hexagonal platelet particles was investigated by computer simulation. The field H(E) was applied perpendicular to the platelet plane which is the easy axis direction of the platelet. The magnetic moments of platelets with a small exchange stiffness constant, A, switch in the normal vortex mode; those of particles with a large A switch in the quasi-coherent rotation mode. The magnetic moments of platelets with a small uniaxial anisotropy constant, K(u), reverse in the normal vortex mode; platelets with a large K(u) reverse in the crater mode. The magnetic moments of a thin platelet switch in the quasi-coherent rotation mode; a thick platelet switches in the normal vortex mode.