First order parametric instability of quasi-surface spin waves in ferromagnetic films

A theory is presented for the first-order (three-wave) parametric instability of a quasi-surface spin wave propagating in a tangentially magnetized ferromagnetic film. It is taken into account that the propagating quasi-surface spin wave is excited by the localized pumping magnetic field (e.g. the field of a microstrip antenna), and the threshold value of this field is calculated. Theoretical results are compared to the results of experiments performed on yttrium-iron-garnet films. >