Vortex Domain Wall Structures and Exchange Coupled Magnetization Switching in Bit Patterned Media

After twenty years study of the exchange spring effect, this effect has shown strong potential in application on the perpendicular record process. It satisfies all the necessary properties required by the perpendicular record process. The exchange coupled patterned media also provide a new way to further increase the data storage in the future. Although studies involve many aspects of the exchange spring effect are taken by experiments and theoretical simulations, a systematic study on a magnetic island perpendicular switching for patterned media is not present. We studied the in-plane and out-of-plane switching process with domain wall movement coupling with the finite boundary condition. Many details like magnetic domain wall, coercive field, remanent magnetization and hysteresis loops are discussed to enhance the magnetic device design. An in-plane vortex domain wall was reported in the simulation and the magnetic loops can be artificially designed.