Progress and Perspective in the Coercivity Analysis of Permanent Magnets via Large Scale Micromagnetic Simulations

The coercivity of permanent magnets is an important factor for the various applications including the electric vehicle motors. Improving the coercivity is highly demanded, however, it is quite sensitive to the microstructure of the magnet. For understanding the relation between the coercivity and the microstructure, the micromagnetic simulations of the permanent magnets have been studied extensively. Recently, as improving the computer performance and applying numerical techniques, such as the energy minimization, we can treat a multi-grain permanent magnet model in sub-micrometer scale. Hence, the effects of the magnetic grain size, the grain orientation and the magnetic properties of the grain boundary have been analyzed by the micromagnetic simulation. In addition, combining the micromagnetic simulation and the path analysis method make the thermal effect analysis enable. In this paper we summarize the foundation of the micromagnetic simulation for the coercivity analysis and review the studies on the coercivity analyses of the permanent magnet by using micromagnetic simulations.