Precessional Magnetization Reversal in Composite Patterned Media: Dependence on Applied Field Parameters

Precessional reversal in composite patterned media elements has been studied for various applied field parameters. The decrease of the percentage of the elements covered by the applied field leads to a rapid increase of the reversal field and decrease of the critical rise time required for precessional reversal. For weak and strong applied fields, the reversal time respectively was found to decrease and increase with an increase of the applied field strength and decrease of the rise time. For certain (large) values of the applied field strength and pulse duration bands of non-reversal can be obtained. This behavior is associated with multiple precessional oscillations between two equilibrium states. Such oscillations can be eliminated by properly choosing the field pulse duration and element damping constant.