Fast precessional reversal in perpendicular composite patterned media

Magnetization reversal mechanisms in composite exchange-coupled dual-layer (composite) patterned media are allowed in the regime of precessional reversal, which is characterized by substantially reduced reversal fields. An important property of precessional reversal in composite patterned media is that it can occur for recording field rise times of more than an order larger than those in patterned media comprising homogeneous elements. These longer rise times can be allowed by realistic recording systems even for materials with ultrahigh coercivity. The reversal field and rise times required for precessional reversal can be controlled by varying the soft layer parameters and coupling strength between the layers.