Energy surface model and magnetization switching for exchange coupled magnetic particles

This paper describes the energy surface model for two exchange coupled magnetic particles and a study of the critical switching field in this coupled system. It is shown that for static switching, the total energy is continuously reduced during the reversal process. The critical switching fields versus applied field angle can be directly obtained from the energy surface model. The results are in good agreement with micromagnetic simulation. For a fast dynamic switching with small damping, the critical switching field may be further reduced. In addition, it is shown that an increase in either Ms or the grain volume of the soft particle will lead to a further reduction of the switching field. This is primarily due to an increase in the Zeeman energy that changes during the reversal.