Intensity of electromagnetic energy radiation by a quiescent ferromagnetic spherical particle placed in a permanent magnetic field

The classical problem of calculating the energy of electromagnetic energy radiated from a ferromagnetic particle is solved for the case when the vector of spontaneous magnetization $\mathbf{M}$ of the ferromagnet differs from that of external permanent magnetic field $\mathbf{H}_0$. The dependence of electromagnetic radiation intensity on the product $\kappa R$ (where $\kappa=\omega_0/c$ is the wavevector, $R$ is the radius of the particle, and $\omega_0=\gamma_eH_0$ is the precession frequency of transverse component $\mathbf{M}_\perp$ of the magnetization $(\mathbf{M}=(\mathbf{M}_\perp, \mathbf{M}_z))$ is derived.