Abstract
The micro-magnetic simulation based on the coherent rotation model assuming that the magnetization in a crystal grain rotates uniformly, could not reproduce a actual M-H loop of the perpendicular magnetic recording medium. We studied two new simulation models of a perpendicular magnetic recording medium to reproduce the actual M-H loop. One model, considering existence of layer of small anisotropy energy as an initial growth layer, caused insufficient reduction of coercive force. The other model was the incoherent rotation model considering decrease of intra-grain exchange coupling. This model could reproduce the coercive force of an experiment well. In case of the intra-grain exchange coupling A=0.15x10^<-11>J/m, we obtained Hο/Hκ=0.23, which was in agreement with the actual CoCrPtB film. We found that it is necessary to increase the number of division of the particle in the direction of magnetic layer with decreasing the value of A.
