Coercivity of permanent magnetic thin film.

The coercivity of magnetic thin film having a two-dimensional easy-axis distribution is investigated within the framework of a simple micromagnetic model. It is found that the coercivity decreases from 0.14H(K) to a minimum of 0.07H(K) as thickness increases, where H(K) is the anisotropy field. It is substantially lower than that given by the Stoner-Wohlfarth model and is consistent with available experimental data. The calculated hysteresis loop and the initial magnetization curve are also in good agreement with experiments.