  The spectrum of localized excitations in an anisotropic one-dimensional
ferromagnet containing a spin cluster of arbitrary size is found exactly within
the framework of the discrete Takeno-Homma model. The boundaries of stability
of spin nanoclusters are determined, depending on their size, and the exchange
and the anisotropy parameter of the ferromagnet. The problem of the spin waves
scattering against nanoclusters is solved and explicit analytical expressions
for their reflection and transmission coefficients are obtained. A model of a
metamaterial consisting of weakly interacting magnetic molecular nanoclusters
and possessing revealed dynamic properties is proposed.
