High-power effects in thin films at oblique polarizing fields

The first results of the behavior of ferromagnetic thin films with an oblique polarizing dc field at high power levels are given. After having verified the characteristics which were observed at a low level by other authors, the subsidiary absorption appearing on the low-field side of the resonance curves and the onset of the uniform mode saturation were particularly studied. Concerning the subsidiary absorption, the variations of its maximum amplitude as a function of the polarization angle Φ with the variations of the angle α, between the magnetization vector and the normal, to the film as a function of the same angle Φ were compared. The amplitude and the angle α have nearly the same variation law with Φ. Concerning the onset of the uniform mode saturation, the variations of are given as a function of the power level. At moderate power levels, we have observed either a positive or a negative slope depending on the polarization angle. The sign of the slopes are interpreted from Schlömann\´s theory, and it is shown that only degenerate spin waves of short wavelength are created when the polarization direction is near the normal; but scattering to spin waves of large wavelength becomes possible as soon as the polarizing angle Φ rises eight degrees.