Rotationally invariant theory of magnetoacoustic wave attenuation in cubic ferromagnets

Rotationally invariant theory is used to study the effect of magnetization relaxation on the spectrum of magnetoacoustic waves propagating in a cubic ferromagnet with an induced uniaxial anisotropy along the [011] direction. It is found that the inclusion of rotationally invariant terms leads to certain contributions to the propagation velocity and rate of attenuation of magnetoelastic waves, thus increasing the degree of anisotropy of these characteristics. Among different types of coupled waves, only quasi-sound modes exhibit a relaxation nature in the region of magnetic phase stability loss. The introduction of dissipation and rotational invariance affects the acoustic birefringence, while the latter gives rise to an additional term in the expression for the phase shift.