The effect of dipolar interactions in clusters of magnetic nanocrystals

Paper i proceeding, 2010

Monte Carlo simulations are carried out to evaluate the effective magnetic moment µeff of clusters containing 100 magnetic nanocrystals (MNCs) in a low magnetic field. The true value of the initial magnetic susceptibility, i.e. x0=∂M/∂H at zero field, can be assesed from µeff. Resuslts show that the dipolar interaction contribute to reduce the efeective magnetic moment. Below a threshold value near the low-field region, clusters of MNCs with smaller diameters possess a larger effective magnetic moment per unit volume compared to clusters with larger MNCs. This is of particular interest for bio-sensing systems relying on the magnetic responce of magnetic multi-core nanoparticles in the low-field region.