Monte Carlo simulation of magnetic nanoparticle systems

We use the Monte Carlo method to study the influence of the low field on the blocking temperature of magnetic nanoparticle systems at different sample conditions, namely the poly-dispersity and the concentration. We find the increase of the blocking temperature at the low field in the dilute sample, and the slow decrease in the concentrated sample. We extract the barrier distribution to explain and compare the magnetic properties of two above samples. We also provide short discussions about the origin of the increase of the peak temperature at low field and the influence of the interaction on the blocking state of particles in the high field.