Experimental Study on the Magnetic and Magnetocaloric Properties of Two Perovskite Compositions, La0.7Nd0.1Sr0.2MnO3 and La0.7Nd0.1Sr0.2Mn0.96In0.04O3, and Their Effect on Chemical Stability in Memory Devices

The chemical stability effect was investigated using two perovskite compositions, La 0.7 Nd 0.1 Sr 0.2 MnO 3 and La 0.7 Nd 0.1 Sr 0.2 Mn 0.96 In 0.04 O 3 . Synthesis of these perovskites was carried out by the sol–gel method. X-ray powder diffraction study, coupled with Rietveld refinement, revealed a rhombohedral structure with the R 3 ¯ c space group. The magnetic investigation showed that both compositions exhibit a second-order phase transition. La 0.7 Nd 0.1 Sr 0.2 MnO 3 has a Curie temperature T C of 290 K and maximum magnetic entropy change value of 4.79 J kg −1 K −1 , while La 0.7 Nd 0.1 Sr 0.2 Mn 0.96 In 0.04 O 3 has a Curie temperature T C of 277 K and maximum magnetic entropy change value of 6.2 J kg −1 K −1 . The critical properties of these compositions were analyzed and found to obey the mean-field model for La 0.7 Nd 0.1 Sr 0.2 Mn 0.96 In 0.04 O 3 and the Heisenberg model for La 0.7 Nd 0.1 Sr 0.2 MnO 3 .