The objective of this research project has been to study the interaction between the magnetic particles of rare earth Nd2Fe14B bonded magnets. We used a finite element simulation package, which uses a scalar potential to calculate demagnetizing fields and includes exchange interaction and magnetocrystalline anisotropy. The time evolution is governed by the Landau-Lifshitz-Gilbert equation of motion.
First, the influence of different mesh sizes was investigated for a single and a pair of two parallel particles. Then the influence of a non uniform distribution of easy anisotropy axes was studied. Finally, a T shaped arrangement of the particles was simulated.
Section 2.1 gives more details and plots of the finite element meshes and distribution of anisotropy axes for the single particle. Sections 2.2 and 2.3 give that information for H shaped and T shaped arrangements of the particles respectively.
Simulation results such as demagnetization curves and numerical data of remanence and coercivity are given in section 3. The magnetization distribution in remanent and demagnetized state is given in sections 4 and 5. More data obtained from the simulations (contributions to the total energy, switching time) and some comments on the computational effort (CPU time, memory requirements, etc.) are summarized in section 6.