The role of microstructure in micromagnetic models of longitudinal thin film magnetic media

A micromagnetic model of thin-film media in which the assumed microstructure of the film may be freely varied is presented. A variety of simulation results illustrating the role of microstructure are presented. It is concluded that the magnetic properties of thin films are determined not only by the properties of individual grains and the nature of the coupling between them, but also by the spatial arrangement of grains, or the microstructure of the film. In micromagnetic models, the choice of a particular, assumed microstructure will affect the predicted reversal mode and thus the hysteresis properties of the film. More significantly, the assumed microstructure may totally dominate the development of small-scale structures such as sawtooth transitions, flux closure, and magnetization ripple. It must therefore be expected that microstructure plays an important role in the prediction of media noise, and in the performance of real media