On the hierarchy of the characteristic lengths of nanowires magnetization

Using computer simulation of magnetization in a polycrystalline ferromagnetic nanowire, we demonstrate the occurrence of the characteristic spatial scale in the distribution of magnetization unrelated to the domain wall or crystallite size. This is the stochastic domain size. We show that this length not only manifests itself in the analysis of magnetization distribution but is included in the spectral density of the force pinning a domain wall to inhomogeneities of the crystallographic anisotropy. The parameters of a stochastic domain, including the constant and distribution of axes directions of the effective anisotropy, are analytically calculated.