Magnetocaloric effect simulation in La0.5Sm0.2Sr0.3MnO3 and La0.5Sm0.2Sr0.3Mn0.95Fe0.05O3 manganites through critical exponents

In this paper, an effective calculation method resulting from the combination of Landau theory and the Arrott-Noakes equation is reported. The magnetic entropy change, -Delta S-M, in a random ferromagnetic system is simulated. A phase shift from paramagnetic to ferromagnetic behavior is observed in these complex magnetic systems. Their critical behavior was ascertained by magnetization measurements and magnetocaloric computations. The critical exponents of the La0.5Sm0.2Sr0.3MnO3 and La0.5Sm0.2Sr0.3Mn0.95Fe0.05O3 manganites were discovered to be (0.43; 1.19; 3.78), and (0.52; 1.45; 3.78), respectively, using modified Arrott plots (applied to Tricritical mean-field, 3D-Ising, and 3D-Heisenberg models) and the Kouvel-Fisher technique. The critical exponents obtained from the study were used to investigate the Landau model by employing the Gibbs free energy to simulate isotherms of magnetization M(mu H-0, T) and the curves of -Delta S-M(mu H-0, T). The findings indicate that short-range interactions are critical in determining the magnetic characteristics and are consistent with the 3D Heisenberg and 3D Ising models.