Monte Carlo simulations of small interacting magnetic particles

We study the aggregation process of small magnetic particles simulating the situation that occurs in the evaporation deposition technique on a two-dimensional substrate. Monte Carlo simulations are used and the particles interact via dipolar interactions. We characterise the clusters produced in the aggregation process by a fractal dimensionality. We show that there is a simple relation between the magnetisation and the fractal dimensionality. We also study the behavior of a mixture of magnetic and non magnetic particles. In this case there is a tendency toward a segregation of the magnetic and non-magnetic components. We define a parameter to characterize this segregation and we study its temperature dependence.