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

Abstract The magnetocaloric effect in the bilayered Ruddlesden–Popper perovskites La 1.4 (Sr 1− x Ba x ) 1.6 Mn 2 O 7 (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 T C for all samples. The experimental results indicate that T C decreases from 161 to 94 K with increasing Ba substitution. With increasing Ba concentration, an increase in the values of magnetic entropy is observed ( 1.95 J k g − 1 K − 1 ≤ | Δ S M max | ≤ 2.84 J k g − 1 K − 1 ) at Δ H  = 2 T.