ABSTRACT

Magneto elastic waves can be excited either ‘magnetically’, when AC magnetization is directly excited by AC magnetic field, or ‘elastically’, when AC elastic displacement is directly excited by some mechanic forces. Elastic excitation (as well as receiving) can be realized, e.g., with the use of a piezoelectric transducer pasted to the ferrite sample. But in most cases, the waves are excited at quasimagnetic half-branches, far from crossing points, and the elastic displacements can be neglected, as well as the influence of magnetoelastic coupling on the spectrum. The magnetoelastic coupling should result in the increase of the longitudinalpumping threshold. This becomes especially clear if the readers use the coupled-mode ‘language’: the parametrically excited spin waves excite linearly the elastic waves, and, therefore, the damping of spin waves and, hence, the threshold increase. The presence of two magnetoelastic branches allows the conservation laws for longitudinal pumping to be satisfied in a degenerate, as well as in a nondegenerate, case.