Magnetocaloric effect in layered perovskite manganese oxide La1.4(Sr1−xBax)1.6Mn2O7 (0 ≤ x ≤ 0.6) bulk materials

The magnetocaloric effect in the bilayered Ruddlesden-Popper perovskites La1.4(Sr1−xBax)1.6Mn2O7 (0 ≤ x ≤ 0.6) prepared by sol-gel methods have been investigated. The dependence of magnetization M on applied magnetic field H and temperature T was measured carefully near the Curie temperature TC for all samples. The experimental results indicate that TC decreases from 161 to 94 K with increasing Ba substitution. With increasing Ba concentration, an increase in the values of magnetic entropy is observed (1.95Jkg−1K−1≤|ΔSMmax|≤2.84Jkg−1K−1) at ΔH = 2 T.