Computer simulation to investigate magnetic and wave‐absorbing characteristics of iron nanoparticles

Computer simulations were carried out to investigate the magnetic and wave-absorbing characteristics of iron nanoparticles. The magnetic properties were found to depend on the shape, aggregation, and array of the nanoparticles. Nanoparticle systems were simulated using a molecular dynamics (MD) method, and the resulting configurations were used to compute the magnetic properties of the systems. In this work, microdot magnetic dipoles were assumed to localize on the iron atoms of nanoparticles. The dynamics of these magnetic dipoles under an external magnetic field were simulated by solving the Landau-Lifshitz-Gilbert equation numerically. The energy loss of a system under an external magnetic field was computed from the hysteresis curve and was correlated with the wave-absorbing characteristic of the system. The findings suggested that the disk-shaped iron particles had a greater hysteresis loss energy than the ball-shaped iron particles. It was also found that the aggregation of nanoparticles apparently reduced the wave-absorbing characteristic of the system. All the outcomes were in good agreement with the experimental measurements.