Internal magnetostatic waves at the boundary of a magnetization jump

It is demonstrated that internal magnetostatic waves (IMW) can propagate in the gap between two ferrite plates with different values of magnetization. A dispersion curve is presented for IMW propagation in the case of a two-layer structure comprising a YIG layer with a magnetization of 1750 G and a layer with a magnetization of 2800 G; the IMW frequency is 3-4 GHz. The IMW has a pronounced surface character and in the phi = 90 deg direction (where phi is the angle between the constant magnetic field and the wave vector) it is strictly unidirectional.