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

Abstract

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=0.05T indicate a monotonic drop in the Curie temperature (TC) from 270K for x=0.0–112K 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 5T applied change in the magnetic field are 3.64 and 3.12J/kgK for x=0 and x=0.075 samples respectively. Under an applied magnetic field of 5T, the relative cooling power (RCP) values are found between 243 and 256J/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.