Critical behaviors and Magnetocaloric Effect in Mixed-Spin–(5 2,1) Hexagonal Nanowire with Monte Carlo Simulation

The magnetic properties and magnetocaloric effects of a mixed-spin Ising model composed of spins (The magnetic properties and magnetocaloric effects of a mixed-spin Ising model composed of spins (S = 1) and (σ = 5/2) on a hexagonal nanowire structure have been investigated using Monte Carlo simulations based on the Metropolis algorithm. The effects of exchange couplings, crystal fields, magnetic fields, and temperature on the magnetization, susceptibility, order parameter, compensation points, entropy, and adiabatic temperature have been analyzed in detail. This study reveals the existence of interesting critical phenomena, particularly the compensation behavior. Furthermore, the ground-state phase diagrams in the (J C /|J|), (D C /|J|, D S /|J|), and (J,h/|J|) planes were established, showing multiple stable configurations that are highly sensitive to exchange interactions and crystal fields. The compensation points appear for specific ranges of the system parameters. It was found that the compensation temperature emerges when (J C /|J| > 0.1) and ((D C /|J| > 0.5) for the spin. [Formula: see text] sublattice, while the (J S ) and (D S ) parameters show no threshold effect. In this case, the compensation temperature remains constant. Regarding the magnetocaloric effect, characterized by the magnetic entropy change (ΔS m ) and the adiabatic temperature change (ΔT ad ) significant variations were observed around the compensation temperature (T comp ) and the critical temperature (T C ), indicating a strong potential for advanced magnetic cooling applications