Magnetocaloric properties of FM/AFM core/shell nanoparticles: a Monte Carlo simulation study

Abstract

In the present work, magnetocaloric properties of FM/AFM core/shell nanoparticles have been studied by using detailed Monte Carlo simulations. Thermal variation of isothermal magnetic entropy change of the core, shell, interface part and total nanoparticle with a spherical shape for various magnetic fields strengths have been examined. Also, dependence of the isothermal magnetic entropy change on the size and geometry of the nanoparticle has been analysed by considering the variation of the shape of the nanoparticle from oblate and prolate to a spherical one. Moreover, for the same shape evolution, cooling capacity (q) and maximum value of the entropy change have been presented as a function of applied magnetic field. Maximum value of the isothermal magnetic entropy change has been shown to take larger values as the applied magnetic field increases. Our numerical results suggest a linear relationship as $$q \sim bh_{max}$$ between cooling capacity and magnetic field which is in accordance with the recent studies. A scaling behaviour as $$|\Delta S_{M}|_{max}\sim h_{max}^c$$ has also been obtained between maximum value of the magnetic entropy change and magnetic field.