Spin excitations in a Ferromagnetic Nanorice-type Cluster

Abstract

In the paper, dipole-exchange spin excitations in a composite nanorice-type nanoparticle (prolate rotation ellipsoid) are investigated theoretically. A nanorice with a non-magnetic core and a shell composed of an uniaxial ferromagnet is considered. Spin dynamics in the above-described nanosystem is described using the linearized Landau-Lifshitz equation (in the magnetostatic approximation) with the addends that consider the magnetic dipole-dipole interaction, the exchange interaction and the anisotropy effects. An equation for the magnetic potential of the above-described spin excitations is obtained. For the case of a thin shell, a solution for the above-mentioned equation in the form of a combination of the generalized spheroidal functions is proposed. For the above-described case, a dispersion relation for such spin excitations is also found.