Singularity in high-frequency susceptibility of thin magnetic films with uniaxial anisotropy

A sharp peak of magnetic susceptibility has been observed in the ferromagne tic resonance spectra of uniaxial magnetic films placed in a planar field d irected orthogonal to the easy magnetization axis, along which a pumping hi gh-frequency magnetic field has been oriented. The peak width is considerab ly narrower than the line width of the uniform ferromagnetic resonance, and its position in a field equal to the film anisotropy field does not depend on the pumping frequency. The nature of the peak is associated with a dras tic increase in the static transverse susceptibility of the film in the vic inity of the anisotropy field. It is shown phenomenologically that the peak can be observed only for quality samples with small angular and amplitude dispersion of the uniaxial anisotropy. (C) 2001 MAIK "Nauka/Interperiodica" .