Shape modes in the ferromagnetic resonance of small rectangular elements

Ferromagnetic resonance experiments were performed on a series of thick yttrium–iron–garnet films. Due to the finite surface to volume ratio, the distribution of the internal field is bimodal, and distinct “shape” and “volume” modes can be observed. The origin of the shape modes is magnetostatic, and they are localized near the edges, corners, and surfaces. The shape modes are located at a higher field than the main volume mode in parallel, and below the volume mode in perpendicular configuration. A crossover between these modes at a critical angle is observed.