Magnetocaloric properties of Nd_0.5Ca_0.5−xSr_xMnO₃(0.0≤x≤0.5) manganites

Abstract

We report in this paper the magnetic and magnetocaloric properties of polycristalline Nd0.5Ca0.5−xSrxMnO3 (0.0≤x≤0.5) compounds. Our samples were synthesized using the solid-solid state reaction method at high temperatures. Structural studies showed that our samples are single phase and crystallize in the orthorhombic system with Pnma space group for 0.0≤x≤0.3 and Imma space group for x = 0.4 and 0.5. The substitution of Ca by Sr destroyed the charge ordered state observed in the parent compound and induced a ferromagnetic phase at low temperatures. From isothermal magnetization versus magnetic applied field we deduced the magnetic entropy change . The maximum value of reached 3.89 J/kgK for x = 0.3 under . Our results are interesting enough and suggest that these materials may be suitable candidates as working substances in magnetic refrigeration near room temperature.