Static and dynamic properties of a ferrite-garnet film in the neighborhood of orientational phase transitions

The static susceptibility and the spectrum of a magnetic-resonance mode of a single-crystal garnet-ferrite film with a domain structure are experimentally investigated. It is found that, in a magnetic field perpendicular to the film plane, these characteristics have features associated with the reorientation of the domain structure. The spin-wave spectrum of the film is calculated on the basis of the domain structure model proposed. It is shown that the experimentally observed features of the spectrum can be accounted for by the reorientation of magnetizations in the domains. A good agreement is obtained between experimental and theoretical values of the gap in the spin-wave spectrum at the “starting and end points of reorientation.”