Numerical investigation on the magnetic field of cylindrical permanent magnet for magnetic nanoparticles application

With the development of nanotechnology, magnetic nanoparticles (MNPs) have been playing a critical role in this field because of their special magnetic features, i.e., the MNPs can be “remotely” controlled by external magnetic field. To take full advantage of the potential of MNPs, exact analysis of magnetic field generated by magnet and magnetic force exerted on MNPs are extremely significant. In present work, the magnetic field of cylindrical permanent magnet is calculated by the equivalent current source method, and the magnetic force is computed by an effective moment method which regards MNPs as magnetic point dipoles. The results derived from the equivalent current source method and that calculated by finite-element-analysis (FEA) software, Ansys, are compared. Besides, the influence of the dimension of cylindrical permanent magnet on magnetic force is investigated.