Nonlinear oscillations of the magnetization in small cylindrical ferromagnetic particles

Abstract

The radially symmetric nonlinear oscillations of the magnetization in small cylindrical particles of a ferromagnet are considered in the cases of free and fixed boundary conditions at the lateral surface of the particles. It is found that even for nonlinear oscillations of small amplitude the dependence of the frequency on the amplitude of the oscillations is rather complicated and can include a series of bifurcations. The character of the oscillations depends substantially on the boundary conditions; for example, for free boundary conditions the solutions exhibit bifurcations that are not present in the case of fixed boundary conditions. We discuss the possibilities for generalizing the results to the case of oscillations in a cylinder with a more complicated angular dependence and to the case of radially symmetric oscillations in a spherical particle.