Exploration of Magnetic and Magnetocaloric Properties of a Sandwiched Graphene-Fullerene Ferromagnetic System

Abstract The dynamic magnetic properties and magnetocaloric effect of a sandwiched graphene‑fullerene composite are studied via Monte Carlo simulations of a mixed‑spin (1, 5/2) Ising model. The crystal field Db dominates the response, while increasing its strength lowers the phase transition temperature, enhances the entropy change, and shifts it to lower temperatures. Stronger exchange couplings Jab and Jb raise the transition temperature but reduce the entropy change, revealing a trade‑off. The amplitude of the oscillating field h0 dramatically increases the entropy change at the cost of narrowing the temperature range. The bias field hb stabilizes ferromagnetic order, while the period τ has a weaker effect. The relative cooling power is optimized at moderate crystal field, weak couplings, and optimal amplitude. This system is promising for Magnetocaloric effect.