Influence of the inhomogeneity of local magnetic parameters on the curves of magnetization in an ensemble of Fe3C ferromagnetic nanoparticles encapsulated in carbon nanotubes

Abstract

Methods have been proposed and tested for analyzing local magnetic parameters in a system of single-domain ferromagnetic nanoparticles using their magnetization curves. The magnetic inhomogeneity in ensembles of Fe3C nanoparticles encapsulated in carbon nanotubes has been investigated. It has been established that the Fe3C nanoparticles encapsulated in carbon nanotubes are characterized by two-modal distribution functions of the local magnetic anisotropy energy. The particle distribution over the blocking temperature is reconstructed from the experimental temperature dependence of the coercive force. The allowance made for the inhomogeneity of the local magnetic parameters of the Fe3C nanoparticles, which were studied by the proposed methods, explains the discrepancy between the magnetic anisotropy energy determined by the method of the magnetization approaching saturation and the magnetic anisotropy energy estimated from the coercive force of single-domain nanoparticles.