Effect of iron substitution on the structural, magnetic and magnetocaloric properties of Pr0.6Ca0.1Sr0.3Mn1−xFexO3 (0 ⩽ x ⩽ 0.075) manganites

The effects of partial substitution of manganese by iron on the physical properties of Pr0.6Ca0.1Sr0.3Mn1−xFexO3 (0 ⩽ x ⩽ 0.075) were investigated experimentally. Our samples were synthesized using the Pechini sol-gel method. X-ray diffraction analysis shows that our compounds crystallize in the orthorhombic structure with the Pbnm space group. Magnetic measurements show that all our materials exhibit a paramagnetic-ferromagnetic transition with decreasing temperature. The M(T) curves at μ0H = 0.05 T indicate a monotonic drop in the Curie temperature (TC) from 270 K for x = 0.0-112 K for x = 0.075 as the Fe concentration is increased. The results of electrical resistivity versus temperature measurements show that all our samples exhibit a metallic behavior at low temperature. For higher values of temperature, metal-insulator transition is seen at temperature Tp. From isothermal magnetization versus magnetic applied field, we deduced the magnetic entropy change ΔSM. The maximum values of the magnetic entropy change (-ΔSMmax) at 5 T applied change in the magnetic field are 3.64 and 3.12 J/kg K for x = 0 and x = 0.075 samples respectively. Under an applied magnetic field of 5 T, the relative cooling power (RCP) values are found between 243 and 256 J/kg for undoped sample and x = 0.075 respectively. Our results are interesting enough and suggest that these materials may be suitable candidates as working substances in magnetic refrigeration.