Bloch wall dynamics in garnet films with low losses in strong promoting fields

The domain boundaries dynamics in the YBiFeGa system film with the perpendicular magnetic anisotropy and low losses in the ferromagnetic resonance is studied. The measurements are accomplished by radial extension of the cylindrical magnetic domains in the strong promoting pulse fields and in the presence of the direct magnetic field, applied in the film plane. The method of the high-velocity image registration was applied. The character of the wall velocity dependence on the promoting field sections for the wall sections, oriented in parallel and perpendicular to the field in the film plane, is established. In all the cases the above dependence contains the area of saturation; the velocity in this area essentially increases with the field growth in the plane. The obtained data do not agree with the theory formulae. The possible explanation of this divergence is proposed. The appearance of the wall spatial-periodical distortions by motion is discussed