Size effect on the hysteresis characteristics of a system of interacting core/shell nanoparticles

In this work, a model of interacting two-phase core/shell nanoparticles is presented. An analysis of the effect of exchange coupling, size and magnetic interaction between Fe/Fe3O4 nanoparticles on the coercive field Hc, the remanent saturation magnetisation Mrs and the saturation magnetisation Ms has been carried out. We show that the hysteresis characteristics grow together with the size of nanoparticles. Changing the exchange interaction constant leads to a nonmonotonic change of Hc and Mrs. Magnetic dipole-dipole interaction between core/shell nanoparticles results in a decrease of Hc and Mrs, due to the chaotisation of magnetic moments of the interacting nanoparticles.