A Metropolis study of the isothermal magnetic entropy change in spin-1/2 Ising model

Abstract

Magnetic refrigeration is a sound, environment friendly alternative to conventional refrigeration techniques. Isothermal magnetic entropy change, for a magnetic substance, is an important quantity to be investigated for determining its potential for Magnetic refrigeration. We have performed extensive Monte Carlo simulations with Metropolis single spin-flip algorithm on spin-1/2 Ising model on a square Bravais lattice to study the change in the magnetic entropy, ΔSm for five values of the external magnetic field, where spin-field energies are either equal to or greater than the in-plane ferromagnetic coupling strength. Binder’s fourth order magnetization cumulant is employed for the determination of the critical point. We observe the peak of ΔSm to coincide with the critical point or the Curie point. With a gradual increase in the magnitude of the field, the peak value of ΔSm increases. The behaviour of isothermal magnetic entropy change is systematic over the entire range of temperature, under observation. This implies such materials, which obey nearest neighbour Ising interactions, are good candidates for Magnetocaloric applications.