Magnetic entropy change of the layered perovskites La2-2xSr1+2xMn2O7
Abstract
Magnetocaloric properties of perovskite-type manganese oxides with double Mn-O layers of composition La2−2xSr1+2xMn2O7 (x=0.33 and 0.4) have been investigated. A broad peak of magnetic entropy change (−ΔSM) was observed at the Curie temperature. The shape of −ΔSM is strongly dependent on the Sr concentration. In contrast to Ln1−xAxMnO3 perovskites, the distinct curvilinear shape of −ΔSM for perovskites with double Mn-O layers shows different magnetic mechanisms arising from magnetocrystalline anisotropy.