Analysis of Static and Quasidynamic Behavior of Magnetostatically Coupled Thin Magnetic Films

When two superposed films exert fields on each other, their static and dynamic behaviors change. The following method of analysis is used to study the behavior: The stable states are found by minimizing the total free energy of the films. Then constant-field contours are plotted in the θ1,-θ2 plane (θ's being the stable orientations of the magnetization vectors). In examining the plot, one can predict multiple stable states, switching, threshold, hysteresis, and the detailed paths of magnetization change as a function of applied field. The solution is carried out by a numerical process which permits evaluation of the following effects: the variation of the degrees of symmetries of the anisotropy energies, the relative orientation between the films, the coupling strength, and the drive-line layout. An example is carried out in sufficient detail for illustrative purposes.