The theory of electromagnetic wave propagation in a ferromagnetic film

Analysis of Magnetostatic Modes Modified by Exchange and Anisotropy Energies

“…To search for surface wave, we now find out and discuss the spin mode dispersion. As we know, the general magnetostatic potential should satisfy the electromagnetic boundary conditions that the continuity of tangential component of h and normal b must be ensured Substituting (8) and (5) into (lo), we obtain an implicit dispersion relation , / 3 is given by (8). If the wave vector is assumed to be along K,-axis, i.e., there is only the contribution of K y to dispersion equation, (1 1) will approximately become where From (12), it is evident that the surface branch has been modified by the coupling of anisotropy energy and exchange energy.…”

“…Reviews about this area have been given by Patton [4], Wigen [5], Mills [6], and Grunberg [7] which presented representative citations to literatures. Li Yibing et al [8] analysed the electromagnetic propagation in ferromagnetic films by considering the retardation and found some new modes except the similar DE mode, which was the case of long wavelengths; but when the wavelength is shorter, the exchange effect should be considered [2 to 71. Of course, even in the long-wavelength limit, the properties of the surface spin wave will still be affected by this coupling that has been ignored so far.…”

“…The film thickness was measured by light interference. Employing the dispersion relation of (lo),(8), and (9), the microwave spectra were calculated. The resonance field of the modes (nl, tz2) for this sample was determined with a single set of parameters:4nM, = 0.1750 T, H , = -100 Oe, g = 2.00, and D = 5.4 x…”