Study on magnetocapacitance effect of magnetic particle polymer matrix composite system by finite element method

In this paper, the magnetocapacitance effect of magnetic particles Fe3O4 embedded in polymer insulating matrix polydimethylsiloxane is investigated using finite element method by commercial software Comsol Multiphysics. With this method, the process of the capacitance variation under different magnetic field is simulated, and the factors influencing magnetocapacitance effect are studied. In particular, we apply the micro-macro coupling method for simulation analysis due to a large amount of calculation in the actual model. First, a three-dimensional microscopic model is calculated to obtain the effect of the magnetic field on the equivalent permittivity of the composite. The relationship is then substituted into the material property of the macroscopic model to simulate the magnetocapacitance effect. The results show that the composite exhibits magnetocapacitance characteristics that are related to the magnetic field intensity, particle size, and particle concentration. The capacitance value increases with the magnetic field at certain particle size and particle volume fraction. Meanwhile, the capacitance value at the same magnetic field increases with the particle size and particle volume fraction. The numerical results are consistent with the experimental results. The simulation model can provide a reference for research on the magnetocapacitance effect involving similar composite systems composed of magnetic particles and polymer matrix. (C) 2017 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license.