Study of the magnetic and magnetocaloric properties of new perovskite-type materials: La${}_{0.6}$Ba${}_{0.2}$Sr${}_{0.2}$Mn${}_{1-x}$Fe${}_x$O${}_3$

In this paper, we investigated the effect of iron doping on the structural, magnetic and magnetocaloric properties of La${}_{0.6}$Ba${}_{0.2}$Sr${}_{0.2}$Mn${}_{1-x}$Fe${}_x$O${}_3$ (0 < x < 0.06) samples. All the samples crystallized in a rhombohedral system with R $3\overline{c}$ space group. Magnetic measurements showed that our samples undergo a FM–PM transition around the Curie temperature (T${}_c$) which is equal to 349 K, 289 K, and 249 K for x = 0, 0.03, and 0.06, respectively. This decrease in T${}_c$ with the increase in Fe content can be related to the weakness of the Mn${}^{3+}$-O-Mn${}^{4+}$ double exchange interaction. The magnetocaloric effect was estimated by the calculation of the magnetic entropy change (-ΔS${}^{max}$${}_M$) as a function of temperature at different applied magnetic fields. The maximum values of the magnetic entropy change are found to be 2.43 J kg${}^{-1}$ K${}^{-1}$, 2.16 J kg${}^{-1}$ K${}^{-1}$, and 1.65 J kg${}^{-1}$ K${}^{-1}$ under a magnetic field of 5 T for x = 0, 0.03, and 0.06, respectively.