Surface Magnetostatic Modes and Surface Spin Waves

Examination of the spatial configuration of the magnetostatic modes of a ferromagnetic body shows that those modes whose frequency lies between $\ensuremath{\omega}=\ensuremath{\gamma}{({B}_{i}{H}_{i})}^{\frac{1}{2}}$ and $\ensuremath{\omega}=\ensuremath{\gamma}({H}_{i}+2\ensuremath{\pi}M)$ are surface modes. It is also found that the complete spin-wave spectrum consists of a set of surface spin waves in addition to the spin-wave band usually considered. The magnetostatic mode spectrum thus merges smoothly into the spin-wave spectrum.